RALEIGH, N.C. -- The Washington Capitals will be without winger T.J. Oshie for "quite some time," according to Capitals coach Todd Reirden.

Oshie was pushed into the boards by Carolina Hurricanes forward Warren Foegele late into the third period Thursday, crashing shoulder-first. Oshie laid on the ice for several minutes and went directly to the locker room clutching his right arm.

"It's a defenseless player quite a distance from the boards," Reirden said. "It's an extremely dangerous play. He won't be with our team for a while. He won't be playing anytime soon."

The Hurricanes won the game 2-1 to even the series at two games apiece. Game 5 is Saturday in Washington.

Reirden said the play will be reviewed by the Department of Player Safety. The Capitals took offense that there was no major penalty called on the play.

"If the guy hurt, it's a dirty play," captain Alex Ovechkin said. "It has to be not two minutes. It has to be different call."

Foegele, the 23-year-old rookie who has been a breakout offensive star for the Hurricanes during the postseason with three goals in the first four games, was apologetic afterward.

"I was trying to lift his stick, trying to give him a little nudge," Foegele said. "It was a little unfortunate play there. I wasn't trying to hurt him or anything. I hope he's OK."

Oshie missed 12 games during the regular season as he dealt with symptoms from a concussion.

The series turned testy as it shifted to Carolina for Games 3 and 4. In Game 3, Ovechkin fought -- and knocked out -- Carolina rookie Andrei Svechnikov. Svechnikov missed Game 4, as he is in concussion protocol. Carolina lost another top-six forward, Micheal Ferland, in Game 3 to injury. Ferland has no timetable to return, according to Hurricanes coach Rod Brind'Amour. In the first period of Game 3, Carolina forward Jordan Martinook awkwardly collided with the boards and had to be helped off the ice. He was later ruled out of the game with a lower body injury.

When asked about what it would mean if Oshie was out for an extended period, Brind'Amour said: "We have way more injuries than they do, so I don't worry about their team."

Brind'Amour did not see any problem with the play.

"[Oshie] crashed into the boards hard, and that's when the [official's] arm went up, because [Oshie] stayed down," Brind'Amour said. "You don't like to see that, but more than anything, he was just not ready for the hit. You see a lot of hits that are way, way worse than that. So, I think he just went in awkward."

Major League Soccer clubs will be compensated for the costs of developing players from its youth academies who opt to sign their first professional contract with foreign clubs after the league announced on Thursday it will begin complying with FIFA regulations relating to training compensation and solidarity payments.

The decision means MLS clubs will now receive compensation for players they develop, which could reach well into six figures. They will also receive a cut of transfer fees when those players are transferred to clubs in a different country. Conversely, MLS clubs will have to pay these fees to foreign clubs when it pays a transfer fee for incoming players.

"We have been making increasing investments in youth development, and that investment has accelerated over the past few years," said MLS executive vice-president of player relations and competition Todd Durbin of the announcement. "We intend on continuing to make that investment and we want to grow that investment. But in the event that a player that we developed decides to sign overseas, we believe that we should be able to recoup the value of that investment."

Solidarity payments are paid whenever a player is transferred to another club prior to the end of their contract, and that transfer involved moving to another country -- a "change of association" in FIFA, according to world soccer's governing body.

Five percent of the transfer fee is paid to the youth clubs responsible for the player's development between the ages of 12 and 23. The rules also stipulate that when a player signs their first professional contract with a club in a foreign country, or is transferred to a club in a different association, the professional club is obligated to pay training compensation to the youth clubs that developed the player between the ages of 12 and 21. Training compensation is also due when a player is transferred to a club in another country up until the season of his 23rd birthday.

Q&A: What does the decision mean for MLS clubs?

Not everyone is happy with the move by MLS, however. The MLS Players Association, as well as the players' agents, view training compensation and solidarity payments as a glorified tax whose amounts have the potential to kill deals.

In a statement provided to ESPN FC, the MLS Players Association said the league's announcement was "a step backward for the development of soccer in the United States and Canada" and called it an effort by MLS to inhibit player choice.

"Despite claims to the contrary, this move is not about improving youth development," the MLSPA said. "Rather, it is simply about trying to force players to sign with MLS by limiting opportunities abroad."

The MLSPA added: "The fact that training compensation and solidarity payments are paid elsewhere in the world under applicable FIFA regulations is an indefensible justification for MLS's change in position on these issues. The league routinely ignores regulations that protect players under contract with MLS -- like those requiring guaranteed contracts, prohibiting unilateral options and limiting the length of contracts -- yet is now attempting to rely upon these same regulations to limit opportunities for players in youth academies.

"We will review these changes, including the Consent Decree entered into by the U.S. Federation on this subject, and will explore all of our options with other stakeholders."

The United States Soccer Federation (USSF) had forbidden the implementation of training compensation and solidarity payments, which FIFA introduced within its Regulations on the Status and Transfer of Players (RSTP) in the aftermath of the 1995 Bosman decision that granted free agency to players at the end of their contracts.

Among their reasons were fears that RSTP violated child labor laws or would result in litigation on anti-trust grounds by various stakeholders, including the MLS Players Association. The USSF had also in the past contended that a consent decree contained in the court case Fraser vs. MLS -- which stipulated that MLS would not require a transfer fee to be paid for out-of-contract players -- prevented it from enforcing RSTP.

The USSF contends that at a meeting of stakeholders in 2015, opposing viewpoints among youth clubs, professional leagues, and players' unions left the organization caught in the middle.

"Since that time, U.S. Soccer has maintained a position of neutrality on the issue of training compensation and solidarity payments and, accordingly, will not be a party to enforcement of those regulations," a USSF spokesperson told ESPN FC.

The spokesperson added, "We will, however, continue to pass through any claims made by clubs as required by FIFA regulations. This position remains the same regardless of the affiliation of the club making the claim."

The decision is a philosophical shift for MLS and could amount to a considerable financial benefit for its clubs. MLS has never paid or received training compensation and solidarity payments. But as the league's clubs began developing their own youth academies -- investing tens of millions of dollars annually -- it ran into situations where academy products were signing their first professional contracts with foreign clubs. Elsewhere in the world, the academy would have been compensated, but because RSTP was not adhered to in the U.S., the MLS clubs received nothing in return.

One example came in 2016 when current U.S. international Weston McKennie spurned his youth club, FC Dallas, to sign with Bundesliga side Schalke 04. The money invested in McKennie's development was never recovered and the deal removed some incentives for Dallas to make investments in youth development, leaving some clubs questioning MLS's overall commitment to youth development.

Deals like McKennie's will not be reexamined by MLS, but if McKennie is transferred to a team outside of Germany, Dallas -- and not MLS -- would be eligible to receive the entire solidarity payment as a return on player development.

But while MLS is set move forward in the area of training compensation and solidarity payments, the future is less certain for U.S. youth clubs that operate outside of MLS.

In recent years, some clubs had taken the matter of solidarity payments to FIFA's Dispute Resolution Chamber (DRC). A case involving the 2014 transfer of U.S. international DeAndre Yedlin from the Seattle Sounders to Tottenham Hotspur sparked a filing from one of Yedlin's youth clubs, Crossfire Premier. A decision on the case is expected in the coming days.

Two other cases -- one filed by the Dallas Texans regarding Clint Dempsey's 2013 transfer from Tottenham to the Seattle Sounders, and another from Sockers FC Chicago regarding Michael Bradley's transfer from Roma to Toronto FC in 2014 -- were denied by FIFA's DRC last month, for reasons that weren't made public.

LOS ANGELES -- MLS intends to expand to 30 teams, with teams 28 and 29 requiring an expansion fee of $200 million, commissioner Don Garber announced Thursday following a Board of Governors meeting.

Garber said the board had authorized his office to advance into exclusive discussions with St. Louis and Sacramento with an eye toward those two cities being the 28th and 29th teams.

MLS currently has 24 teams and has already confirmed expansion teams in Austin, Miami, and Nashville to join in the coming years.

"In the last 10 years we've been experiencing unprecedented growth for a major league in North America," Garber said. "Expansion has been a key driver of that growth and it really is a great measure of the enormous enthusiasm and the commitment that our fans have in markets both new and old to support our league and our players and to see the sport grow."

Garber said the ownership groups from both cities will make formal presentations to the league's expansion committee in the coming weeks. Part of the process will involve getting to know the respective ownership groups, both of which have investors who are relatively new to the process. Garber hopes a final decision on both cities would be made before this summer's All-Star Game in Orlando in late July.

"We'll be asking them for their formal and final plans for a commitment of corporate support, the final composition of their ownership group, and detailed economics on their funding of both their team operations and their stadium plans," said Garber.

While the league has said at times that it would stop expanding at 28 teams, the announcement was not a surprise. Garber said the strength of the Sacramento and St. Louis bids was part of what drove the Board to decide to expand to 30 teams.

Sacramento's hopes of landing a team were boosted in January when billionaire Ron Burkle became the new lead investor in the Sacramento Republic soccer team. The team currently plays in the second-tier United Soccer League.

Burkle is a co-owner of the NHL's Pittsburgh Penguins with a net worth estimated at $2 billion by Forbes magazine.

The St. Louis group includes World Wide Technology CEO Jim Kavanaugh and the Taylor family, owners of the rental car company Enterprise Holdings.

In a statement released on Thursday, the Sacramento Republic said: "Today is a monumental step in the process and we are closer than ever to reaching our goal of bringing Major League Soccer to Sacramento. There isn't a better fit for MLS than our city and today's announcement is a testament to the strength of Sacramento's bid, and most importantly, to the faith and devotion of Republic FC fans. We will continue our ongoing communication with the Commissioner and with MLS and look forward to finalizing all next steps to deliver MLS to Sacramento."

In terms of what number of teams the league will stop expanding, Garber didn't commit to a definitive number.

"I don't know that we have a firm handle yet on what the final number of teams in the league ought to be," said Garber. "We have a lot of work to do to determine what the future state of MLS is in 10 years and in 20 years. We continue to believe that there are many, many cities across the country that could support an MLS team, with a great stadium and a great fanbase and great local ownership that will invest in the sport in their community."

Garber added that MLS will "take our time" on team 30, though it remains in discussions with the likes of Phoenix, Las Vegas, Detroit and Charlotte.

"We don't want to be unbalanced, but at the same time I think we do need to take a bit of a deep breath and on-board the teams that are going to be coming in over the next number of years."

Garber lauded the bids of Sacramento and St. Louis but also stressed that both ownership group still had work to do. Garber said that Sacramento needed to finalize their corporate sponsorship as well as some elements of the stadium plan. St. Louis needs to finalize its stadium plan as well, but Garber's expectation is that both cities will get their respective bids over the line.

"I've got confidence in both markets," said Garber. "We wouldn't be here today without the confidence of our ownership group to try to put all the elements in place to give them the opportunity to finalize the deal."

Information from The Associated Press was used in this report.

In a perfect world, we would have been talking only about four goals in 11 minutes, one of the wildest quarterfinal matches in history, how Manchester City's season is reduced to a "mere" potential Treble and how Tottenham are 180 minutes away from their first European Cup final. But we live in an imperfect world, and one of the legacies of Wednesday night at the Etihad is the controversy surrounding Fernando Llorente's goal and the use of Video Assistant Referees (VAR).

After speaking to multiple sources, here's an explainer to help sort things out.

Cox: Tactical keys to the Champions League quarterfinals
Ogden: Seven goals and VAR drama. Best CL game ever?

OK, let's get to the point. Was the decision correct?

It was. The reason for all the confusion is that there has been a perfect storm of factors to muddy the waters, from IFAB's decision to tweak the Laws of the Game, to directives given to UEFA referees about how to interpret accidental handballs that lead to goals, to the fact that too many folks simply aren't familiar with the Laws of the Game and their interpretations.

First, we all have to agree that Fernando Llorente's handball was not deliberate because if you think it was, then everything that follows is irrelevant. So based on the directives UEFA use to determine whether a handball is deliberate, his arm was in a natural position, in line with his "body silhouette" and therefore it was an accidental handball, yes?

Sure. He's jumping, his arm is by his side, it's not outstretched... yeah, it's accidental. But I thought IFAB had determined that accidental handballs that lead to a goal would be punished with a free kick...

They did, albeit with certain caveats. In fact, one of the law changes says that it's a free kick if "a player gains control/possession of the ball after it touches their hand/arm and then scores or creates a goal-scoring opportunity." Another one says it's a free kick if "the ball goes into the goal after touching an attacking player's hand/arm."

Llorente's situation was between the two scenarios. The ball touched his arm, but then it hit his hip as well before going into the goal. And you can't really say he gained control of the ball after the touch with the arm, but he did benefit from it as it then hit his hip. The thing to remember is that what you just read is irrelevant here; these rules will apply from next season.

OK, so this season if it's an accidental handball that leads to a goal, then it stands? So why was Neymar's goal in the Champions League final four years ago disallowed?

Well, that incident caused some controversy too, and by the letter of the law some argued it should not have been disallowed. But UEFA has issued directives this season to use a level of discretion.

Regarding Neymar's goal, he obviously gained an advantage from the fact that his header hit his outstretched hand. You can't say it was deliberate (Neymar's good, but not that good) but, quite obviously, if his arm hadn't been out there and it hadn't deflected off it, he wouldn't have scored. So the referee has the discretion to disallow goals like that.

In Llorente's case on Wednesday night, his arm was exactly where it should have been. It was entirely accidental. You can also make the argument that if it had not hit Llorente's arm, it would still have hit his hip and gone in. In other words, it's a discretion call where the referee, in conjunction with the VAR, has to determine what effect the inadvertent touch had on the goal being scored. Some may disagree with the interpretation, but that's the process.

So why did the VAR call the referee, Cuneyt Cakir, to the video monitor?

For two reasons. First, because it's still a huge call and there's an element of discretion. Referees always have the final word on subjective calls. Sometimes they follow what the VAR tells them without checking, sometimes they want to see for themselves. And sometimes VAR wants them to see it.

Second -- and folks have seemingly forgotten this -- the referee didn't have a view of the incident. Llorente's body was in the way. He could guess that it hit a part of his body -- and it's what would have happened until a few months ago in the Champions League, and what will happen until next year in the Premier League -- but it's best if he sees it himself.

What about the fact that, of the various camera angles at the VAR's disposal, Cakir wasn't shown the one from behind the goal, which most clearly shows the ball coming off Llorente's elbow?

What I was told here is that it would not have added anything significant to the decision. Cakir realized as soon as he saw the replays that the ball struck Llorente's arm: you can see the impact it makes on his skin. That part of the equation thus was never in question and additional angles weren't needed.

What did matter was whether his arm was in a natural position (it was: he couldn't have tucked it any closer to his body) and what the material impact was on what happened next. That too was minimal.

More generally, VARs tend not to use behind-the-goal angles because the depth perception isn't great.

So there was no grand conspiracy?

I don't think so. If there had been, they wouldn't have shown Cakir any of the replays, right? The VAR could have just let the goal stand.

It's a cliche because it's true. With just 270 minutes (plus extra time) left to play, anyone can win the Champions League. Liverpool were in the final just a year ago and Barcelona were the last team not named Real Madrid to actually win it. Ajax and Tottenham look like the longshots but have earned their places by taking down Borussia Dortmund, Real Madrid, Manchester City and Juventus in the past two rounds. Plus, thanks to the fact that the quarterfinal and semifinal draws were made at the same time, one of them is already guaranteed to make the final.

So let's take a look at why each team will and won't be lifting the Champions League trophy in Madrid come June 1.

Barcelona: Lionel Messi's magicians

538.com SPI: 93.3
Chance of reaching final: 49 percent
Chance of winning: 34 percent
Semifinal opponent: Liverpool (first leg: Wednesday, May 1, second leg: Tuesday, May 7)

Why They'll Win: The last time Barcelona made it this far, they won the whole thing. In 2015, they'd successfully transitioned out of the "tiki-taka" era and seemed to have a clear succession plan in place: as Lionel Messi aged into his 30s and gradually declined, Neymar would just pick up the slack. Well, four years later, Neymar's gone -- and once again watching the latter rounds of the Champions League from somewhere in Paris -- and Barcelona might be more reliant on Messi than they ever have been.

Messi could have retired last summer and laid claim to owning the best club soccer career we've ever seen but instead, at age 31, he's putting the finishing touches on what might be his best year yet.

Who's leading Europe in goals scored? Messi. Assists? Messi. Through-balls? Messi. Take-ons? That's Eden Hazard, but Messi is second. Messi is the best player of all time because he's basically been the best scorer, creator, passer and dribbler on every field he's ever stepped on. Somehow, in his 15th season, that's more true than it's ever been.

Why They Won't: How do I say this? Their defense... it sucks. It doesn't suck in the grand scheme of European soccer but for a Champions League contender, it sure does. According to expected goals, which uses a variety of factors to put a historical conversion probability on every shot a team takes and concedes, Barcelona have a worse defense than five teams in La Liga alone. They don't dominate possession or press as effectively from the front as they used to, and the guys who always cleaned things up on the back end -- namely, Sergio Busquets and Gerard Pique -- have aged into their 30s.

As such, rather than leveraging the entire team into an 11-man attacking machine, manger Ernesto Valverde has decided to take take his foot off the gas and ask Messi to do everything. On the whole, it's worked out: They're nine points ahead of second place in La Liga and are three games from a fifth Champions League trophy. But being so reliant on a single player -- even if it's the single greatest player -- exposes you to an injury, an off day or a particularly effective opposition game plan.

With their Messi-centric approach, the current iteration of Barcelona basically function as a more talented, better coached version of Argentina. And yeah: you already know how that story goes.

Liverpool: The complete package

538.com SPI: 93.6
Chance of reaching final: 51 percent
Chance of winning: 35 percent
Semifinal opponent: Barcelona (first leg: Wednesday, May 1, second leg: Tuesday, May 7)

Why They'll Win: Remember the helter-skelter Liverpool of the past few years? The one that could nearly blow a 5-0 lead against Roma, lose 4-1 to Tottenham and concede seven combined goals against Swansea and Bournemouth? That team is dead. Long live Simon Mignolet and Ragnar Klavan.

With a slightly less manic, teamwide ball-chasing approach, and a rearguard that now includes arguably the world's best defender (Virgil van Dijk) and the world's best goalkeeper (Alisson), preventing goals has become Liverpool's strength. Based on the number of goals conceded in domestic play -- 20 in 34 games -- Jurgen Klopp's brings the competition's best defense into the semifinals.

The results of knockout games between relatively even teams often have little to do with who dominates space or who creates the better chances. Games typically come down to individual moments: both mistakes and bits of brilliance. After losing last year's final thanks to a Gareth Bale bicycle kick and two outlandish errors by keeper Loris Karius, Liverpool know this better than anyone. Van Dijk and Allison all but eliminate the mistakes on the defensive end, which means any moment of brilliance on the other side of the field is more likely to decide a game.

Liverpool are the only semifinalist with three players -- Mohamed Salah, Roberto Firmino, and Sadio Mane -- who have at least 18 combined goals and assists this season. They had those three players who could win a match last year, too, but now they have the defense to allow them to do it.

Why They Won't: In short, they don't have Messi.

It might seem like picking nits but deeply flawed teams rarely make it this far in the Champions League. That high-flying front three provides the unpredictability of a goal coming from anywhere across the attack, but the team still doesn't have a standout creator who can break down a defense and magic up a chance for a teammate.

Klopp has famously said "no playmaker in the world can be as good as a good counter-pressing situation," but Liverpool aren't quite pressing as aggressively as they have in the past. Plus, among Europe's top five leagues, not a single player in the Liverpool squad is in the top 50 of open-play chances created per 90 minutes.

The lack of a go-to creator hasn't really mattered just yet; they're here and they have the second-best 34-game record in Premier League history. However, some of Liverpool's worst games this season -- the scoreless home draw with City, the 1-0 road loss to Napoli -- have come against teams who made a point of sticking a branch in their gears. Klopp's side take 15 shots per game but they registered just 11 combined attempts over those two matches.

Ajax: The underdogs who play like champions

538.com SPI: 83.4
Chance of reaching final: 51 percent
Chance of winning: 16 percent
Semifinal opponent: Tottenham (first leg: Tuesday, April 30, second leg: Wednesday, May 8)

Why They'll Win: They know who they are. For whatever reason, most teams tend to shift into a slightly more conservative gear when they're away from home. (See: Barcelona and Manchester City combining for just 16 shots in their two road quarterfinal matches.) Not this team, though. Call it "youthful naivete." Call it "the legacy of Total Football," or simply call it "Hakim Ziyech has never met a shot he won't take." Whatever the reason, Ajax play the same way, no matter where they are.

They took a 2-1 deficit into the Santiago Bernabeu against the three-time defending champs and ripped off 16 shots en route to a 4-1 win. They followed that up by taking down Cristiano Ronaldo and Juventus with a thumping 2-1 victory that could have been 5-1 on a different day. Ajax don't grind out victories; they vaporize any team that's in their way.

Ajax's most recent annual revenues were £81 million. As for their fellow semifinalists: Tottenham brought in £372 million, Liverpool £455 million and Barcelona £612 million. The typical underdog knows the odds aren't in their favor, so they play a reactive style that cedes possession, limits the quality of the opposition's chances and creates space on the other end for the occasional counter-attack or set piece. But for every Leicester City and Atletico Madrid, there are countless other teams who tried something similar, failed and were swiftly swept into the dustbin of history.

The reason Ajax have made it this far -- and could go even farther -- isn't that they've played the probabilities properly and caught lightning in a bottle. No, it's this: Even though the finances say they're David, they play like they're Goliath.

Why They Won't: What happens when they can't play their game? Ajax's wins were predicated on passing over, around, underneath and through their opponents. At their best, they systematically create an overwhelming number of chances and enough of them go in. Neither Real Madrid nor Juventus are teams that will automatically dominate possession, and neither side has an effective, swarming counter-press. So, they both allowed Ajax to play they way they want to play.

In three of the four games against those two sides, Barca-bound Frenkie de Jong completed more passes than anyone else on the field. What happens if an opposition press, much like Tottenham did with Chelsea's Jorginho, removes him from build-up play? What if their opponents dominate possession and field position? Can Ajax shift into a more vertical, counter-attacking approach? Or do they need the ball in order to generate enough shots to score?

Of the four remaining teams, Ajax have to answer the most questions.

Tottenham: The never-say-quit collective

538.com SPI: 84.1
Chance of reaching final: 49 percent
Chance of winning: 15 percent
Semifinal opponent: Ajax (first leg: Tuesday, April 30, second leg: Wednesday, May 8)

Why They'll Win: They have one of the best finishers in the world. "But," you say, "Harry Kane is out for the year!" To which I respond: meet this guy.

Forget the emotional torture of VAR. Briefly ignore Pep Guardiola's inability to either wear his hood properly or coach Manchester City beyond the Champions League quarterfinals. City vs. Tottenham was absolute madness but beneath all of the narratives and emotions, there's a simple story: Tottenham converted a high percentage of their chances and City didn't. They each scored four goals but according to FiveThirtyEight, City created 3.7 expected goals worth of chances, while Tottenham registered just 1.6.

Part of that is luck and part of it is that they have Son Heung-Min. Most players over time score roughly around the same number of goals as expected but a handful, like Messi and Son, consistently finish at a much higher rate. Over the past six years, per the website Understat, Son has scored 53 goals in domestic play on just 35.75 expected goals. He's equally adept with either foot -- 30 with his right, 21 with his left -- and if Tottenham manage to lift their first-ever European Cup, they'll be two of the biggest reasons why.

-- Was Man City vs. Spurs the greatest CL game ever?

Why They Won't: Son is suspended for the first leg against Ajax and they're simply running out of players!

Making it this far is an incredible achievement for a club that hasn't signed a new player in either of the past two transfer windows, a first for the Premier League. Mauricio Pochettino has pieced together various lineups that barely contain anything that could legitimately be described as "a midfield" but the club's lack of ambition in squad-building, coupled with a number of key injuries and the regular attrition of a long season, has left them terribly thin.

Against Man City on Wednesday night, Moussa Sissoko -- once an outcast whom Pochettino has been forced to reintegrate into the midfield as a key cog -- went off injured in the first half and was replaced with Fernando Llorente, who is 34 years old and absolutely not a midfielder. The team has plenty of extra central defenders and fullbacks, but there's close to no cover remaining in the midfield or the attack.

Currently one point clear of fifth-place Chelsea (and with a game in hand), Spurs have five close-to-must-win Premier League games left, in addition to the two legs against Ajax and a potential European final. Ajax, Barcelona,and Liverpool all enter this stage of the tournament with what are close to their first-choice XIs fully intact. Even in the best case scenario, Tottenham just won't be able to say the same.