The NHL's 24-team tournament this summer promises to be one of the most unpredictable -- if not fascinating -- postseasons for hockey ever.

The paused season due to the coronavirus pandemic provided significant extra time for injured stars to mend, and there are a number of intriguing lineup decisions that could have an outsized impact, given the shorter length of the qualification-round series.

With teams scheduled to start training camps on Monday (pending NHLPA approval on the protocols), we identified 10 X factors that could determine who hoists the Stanley Cup in October.

1. The Chicago Blackhawks' back end

Since the beginning of the 2018-19 season, the Blackhawks have allowed 505 goals. Only the Red Wings and Senators have allowed more. Chicago's blue line has been a sore spot, and we don't know what we're going to get in August, when they face the mighty Oilers' offense. A year ago, the Blackhawks traded for Calvin de Haan from the Carolina Hurricanes looking to shore up the back end, but the former Islanders first-rounder played just 29 games with Chicago. In December, De Haan underwent shoulder surgery and was supposed to be out four to six months.

"Here we are, and it's been over six months," GM Stan Bowman told me recently. "He was supposed to be out for the year, and now he's someone we expect to play. Calvin was playing pretty well right before he got injured, and our team was playing well then, so I think it's going to be a nice benefit."

Another wild card for Chicago: Brent Seabrook is trying to come back as well. "He had multiple surgeries -- two hips and a shoulder done over a five-, six-week period," Bowman said. "We'll have to see where he's at. He's going to be close, but he went through a lot, so we're not sure. He's not ruled out, but he's probably more questionable."

Oh, and one last (albeit huge) factor for Chicago? The Blackhawks traded Robin Lehner at the trade deadline for Malcolm Subban, but Subban didn't get any starts in Chicago before the season was paused. As a result, coach Jeremy Colliton will likely be riding Corey Crawford throughout, hoping the veteran stays healthy.

2. The New York Rangers' goaltending trio

The Rangers don't have just one starting goaltender. They have three. It's a predicament most teams try to avoid, but the gamble might just work out for the Blueshirts. Consider that this year's tournament is expected to test every team's depth -- and the NHL knows it, as it is allowing teams to carry as many goaltenders as they wish.

A quick refresher: Henrik Lundqvist is the King, but at 38, he's staring down the twilight of his career. Once the Rangers recalled their hotshot prospect, 24-year-old Igor Shesterkin, this season, we knew Lundqvist's days in New York were numbered. Meanwhile, there's also Alexandar Georgiev, whom many expected the Rangers to trade at the deadline. But New York kept him around, as he's quite competent.

Shesterkin might be the best of the three right now, but it would be shocking if Lundqvist didn't get the nod as the starter in the early going, considering his postseason track record. Since 2010, in 22 playoff games in which he faced elimination, Lundqvist has gone 15-7 with two shutouts, a 1.86 goals-against average and a .941 save percentage. Those are hard stats to bench.

3. The St. Louis Blues get their sniper back

After Vladimir Tarasenko dislocated his left shoulder in October, doctors told the Blues that he could be reevaluated in five months. That was a dagger for the defending Stanley Cup champs. But by December, GM Doug Armstrong told me that Tarasenko was so diligent with his rehab that the team "actually tried to slow him down a little bit."

"We told him to spend time with family, take vacations, because when we get into January and he can start going full-barrel, we want him to," Armstrong said.

Because Tarasenko was on long-term injury reserve, the Blues could have spent his salary-cap space ($7.5 million) for a player at the trade deadline, but they would have to get back to being cap-compliant if Tarasenko returned before the regular season. The Blues opted not to add any forwards, instead adding only depth defenseman Marco Scandella.

"There's no player we're going to get that's as good as Vladdy," Armstrong said. "So I'd rather get Vladdy back than spend that money."

Now it appears that the Blues will get their most lethal scorer back just in time. Tarasenko has been back skating with the Blues. "I was really close to coming back playing when the season got delayed, so I got some extra time for recovery and practice to make [my shoulder] more strong," Tarasenko said in a video interview for the Blues website in June. "Everything is good."

4. Who's the guy in goal for the Nashville Predators?

Pekka Rinne is the greatest goaltender in Predators history, and he's only two years removed from his Vezina Trophy-winning season. Three years ago, he led Nashville to the Stanley Cup Final. But he might not be the guy anymore.

Rinne, 37, has 89 career playoff starts, and therefore, conventional logic says he should get the nod. But before the shutdown, Nashville was favoring starts for his longtime backup (and heir apparent), 25-year-old Juuse Saros. When I visited the Predators in December, I chatted with Rinne, and he told me that the two countrymen have a great relationship, so there's no animosity between them. However, Rinne said, he tends to do better when he gets consecutive starts, which makes him not quite so effective as a backup.

"If you play all the time, you have a rhythm," Rinne said. "So it has been an adjustment. At the same time, I feel good about it. I have a great goalie partner. Juuse Saros is an amazing young goalie. He deserves to play. He's played well. He deserves his starts. Even though I wish nothing but the best for him, it's still an adjustment."

It's a delicate situation to balance for John Hynes, who has been behind the bench only since January.

5. A healthy Jake Guentzel returns

By now you've heard ad nauseum about the Pittsburgh Penguins' unrelenting injury luck this season -- and how they somehow overcame it to stay afloat in the playoff race. One of the guys who helped them tread water early was Jake Guentzel. The 25-year-old, coming off his first 40-goal season, had 20 goals in his first 39 games.

Then he took an awkward spill in December, tripping over Ottawa Senators defenseman's Thomas Chabot's stick and crashing into the boards. After shoulder surgery, Guentzel's prognosis was a four-to-six-month recovery, which should have him back in time for the playoffs (he's already skating with teammates in Pittsburgh).

Guentzel admitted to reporters recently that he's "not sure what would have happened if the season played out" on a normal schedule, but now he'll get his shot to complete it. What's more: Pens GM Jim Rutherford -- always looking to go all-in with Sidney Crosby and Evgeni Malkin on the roster -- already secured a reinforcement at forward, trading for Jason Zucker at the trade deadline. Pittsburgh's offense has the potential to be scary good.

6. The Vegas Golden Knights' big trade-deadline acquisition

Sure, the Golden Knights haven't been around for very long, but it's safe to call Marc-Andre Fleury a franchise legend. He backstopped the Golden Knights to their improbable Stanley Cup Final in the inaugural season and has shouldered the brunt of the workload when healthy.

But the Golden Knights did something quite surprising at the trade deadline: They went out and dealt for Robin Lehner, fresh off his Vezina finalist campaign last season with the Islanders and encouraging work this season in Chicago. Lehner got a chance to start only three games in Vegas before the season was paused, but we know he's a high-caliber option in the crease.

Like John Hynes in Nashville, Vegas coach Peter DeBoer had been on the job for only two months before the season was canceled, which isn't exactly enough time to get a full vibe check of the locker room. Whom he elects to start might not be as important as the fact that the Golden Knights have both of these guys in their arsenal. In this unprecedented tournament -- in which one or two positive tests could derail an entire team -- perhaps having two elite level goaltenders will be the key.

7. The New York Islanders' blue line is back

We know the Barry Trotz-led Islanders have an identity: They're a defensively sound group that's typically quite stingy. This season, there were a few hiccups, especially when Adam Pelech tore his Achilles tendon in January. Pelech and Ryan Pulock had taken over for Johnny Boychuk and Nick Leddy as the Isles' top pair. The Pelech and Pulock duo was fantastic and shouldered a ton of the blue-line workload.

Without Pelech, Trotz gave heavier ice time to Boychuk, Leddy and rookie Noah Dobson, and there was a considerable drop-off. (It didn't help that the team doesn't yet fully trust Dobson, as the 20-year-old averaged a hair over 13 minutes per game in his 34 contests). The situation forced GM Lou Lamoriello to trade for his former Devil, Andy Greene, at the trade deadline (though that wasn't a be-all, end-all solution).

Nonetheless, Pelech -- like many stars we wrote off for the season -- should be back. That will bump everyone back to their normal roles, which means that when New York takes the ice again, we could see the best version of the team's blue line.

8. Here come the reinforcements for the Carolina Hurricanes

As Carolina coach Rod Brind'Amour put it on the "ESPN On Ice" podcast in May: "We were one of those teams that, we had a lot of injuries actually at the end, even though we were playing pretty well." A fully loaded Canes roster should be scary.

It begins with Dougie Hamilton, who was in the Norris Trophy conversation when he fractured his left fibula in January. At the time, he was tied for the NHL lead in goals among defensemen (14) and fourth in points (40). Brind'Amour told us that Hamilton will be "definitely ready to go."

But it doesn't stop with Hamilton. "We traded for Sami Vatanen at the trade deadline, but he was actually injured, and we kind of thought he was gonna be able to play," Brind'Amour said. "We were told he was going to be able to play, but he wasn't. So he would have been iffy at best had we started [at the regularly scheduled time]. And now that takes that out of the equation. So that's an interesting one, just because we've never seen him play with us or practice even. That is a wild card, but that's a pretty good wild card. I like having that one in the hole there."

Perhaps those two players will help Carolina get over the hump against the Rangers, whom they drew in the first round. (New York went 4-0 against the Canes this season).

9. What about Bob?

By now, we all know that the Florida Panthers made an extraordinary commitment to Sergei Bobrovsky in free agency, hoping he would be the long-term answer in net. And we all know that the two-time Vezina winner hasn't looked like himself in South Florida. Bobrovsky gets a decent matchup in the first round, going up against the offensively challenged Islanders, a team he's quite familiar with from his Metropolitan Division days.

That said, Bobrovsky doesn't have the best postseason track record -- outside of the Blue Jackets' incredible sweep of the Tampa Bay Lightning in the first round last year -- so he does have something to prove. Perhaps the added rest will play in his favor. He can be incredibly dangerous if he goes on a hot streak. If not, well, this will be more fuel for the fire as we talk about his seven-year, $70 million contract for years to come -- and not in the best light.

10. Finally, which players will opt out?

Ah, this summer's great mystery. It's not just who is available; it's who wants to be available. The NHL and NHLPA have agreed that any player can opt out of the tournament, without a reason, and won't be penalized. Players will need to notify their teams, in writing, three days after the return-to-play protocols are ratified.

Based on conversations with people around the league, there isn't expected to be a mass exodus of players choosing not to play, but we've already heard rumors that there could be a handful. Because families are not allowed to join players until the conference-final round, that could be a factor for some players in choosing not to play, in addition to concerns about their health and safety.