THE BALL SWUNG from Jayson Tatum to Dennis Schroder to Al Horford to Marcus Smart, pinging around the perimeter in search of the best possible shot.

It was Nov. 19, and the Boston Celtics -- already leading by 14 points with just over five minutes to go against LeBron James and the visiting Los Angeles Lakers -- were about to put the finishing touches on an impressive win over their forever rivals.

Smart drove baseline, sucked in two defenders, jumped and fired a pass back to a wide-open Tatum in the left corner directly in front of the Lakers bench.

L.A. coach Frank Vogel, standing 5 feet from Tatum on the baseline, had already started walking toward the referee to call timeout before the dagger 3 fell through the net.

The play encapsulated how things have changed for Boston since November began with a fourth-quarter collapse on their home court against the Chicago Bulls, followed by Smart calling out the team's two young stars, Tatum and Jaylen Brown, and a players-only meeting the next day.

Since then, Boston has ripped off eight wins in its past 11 games entering Wednesday's showdown with the Brooklyn Nets at TD Garden (7:30 p.m. ET on ESPN). Boston, 10-8, has posted the league's best defense over that span and is pushing back into the middle of the Eastern Conference playoff picture.

But Brooklyn's arrival provides a reminder of where the Celtics stand in the East: a clear rung below the Nets and the defending champion Milwaukee Bucks, the conference's two preseason favorites to reach the NBA Finals this season.

Boston spent several years living in that rarified air, both signing and trading for multiple All-Stars en route to a stretch of three conference finals appearances in four seasons. Ultimately, however, the push to hang Banner 18 from the rafters failed, despite the amount of capital -- both in dollars and trade assets -- the Celtics spent trying to do so.

Now, as Boston tries to retool its roster around its All-Star wings and return to championship contention, the Celtics will have to do so without the benefit of the draft picks and assets they had available to them over the past several seasons.

"I can't believe this whole era for them hasn't really worked," one league executive said. "They're stuck in neutral -- and maybe going backwards."

THE CELTICS LOST to James and the Cleveland Cavaliers in the 2018 East finals, but the future seemed much more certain then.

Brown had averaged 19.7 points for the series, while Tatum, in his rookie year, posted 17.9 points, including an iconic dunk over James in the fourth quarter of that Game 7.

The fact Boston did so with both Kyrie Irving and Gordon Hayward watching in street clothes only fueled the belief the East would inevitably tilt back toward the Celtics' favor -- especially once James jumped to L.A. that offseason.

The Celtics entered the 2018-19 season with a roster featuring five either present or future All-Stars: Irving, Brown, Tatum, Hayward and Horford, along with starting-caliber players in Terry Rozier and Marcus Morris Sr. coming off the bench. Future unprotected first-round picks from non-playoff teams -- via the Sacramento Kings and Memphis Grizzlies -- were either expected to net high draft picks or turn into trade options.

In the span of three years, the franchise underwent a steep and steady talent drain:

• Irving, Horford and Morris left via free agency.

• The picks from the Kings and Grizzlies turned into the 14th selection in consecutive seasons, netting Boston a pair of reserve swingmen in Romeo Langford and Aaron Nesmith.

• Rozier was sent to the Charlotte Hornets in the sign-and-trade deal to land Kemba Walker, who was subsequently sent to the Oklahoma City Thunder along with a first-round pick for Horford.

• The trade exception created when Hayward left became two months of Evan Fournier and then Josh Richardson.

• Coach Brad Stevens left the sidelines to replace Danny Ainge as president of basketball operations.

The result? Boston now is short both on high-end talent and high-end assets to build around its young stars.

"Ultimately, you can't keep losing -- albeit flawed -- All-Star talent like Kyrie, Gordon, Kemba, Horford," an Eastern Conference scout said. "That adds up."

Meanwhile, out of Boston's past four drafts, only Robert Williams III appears to have the upside of a long-term starter. Four other first-round picks -- Grant Williams, Payton Pritchard, Langford and Nesmith -- have spent time sliding in and out of the rotation for Stevens and his replacement, coach Ime Udoka. Another high second-rounder, Carsen Edwards, quickly flamed out too.

Even the team's two-way slots -- which teams around the league have turned into high-end rotation players such as Alex Caruso, Duncan Robinson and Luguentz Dort -- have been wasted. For the past two seasons, Boston used theirs on guard Tremont Waters and center Tacko Fall, neither of whom came close to becoming rotation players before being replaced this summer.

"The Celtics the last couple years have had a few really good players," another executive said, "and too many roster spots dedicated to players they drafted who aren't good enough."

But through all the roster and front-office turnover, Boston still has Tatum and Brown.

Last season, seven teams had at least two All-Stars. Five of them were top-four playoff seeds in their respective conferences. The other two were the Lakers, who had James and Anthony Davis miss a combined 63 games, and Tatum, Brown and the Celtics, who finished .500 in the East and were dismissed in five games by Brooklyn in the first round.

"Jaylen and Jayson aren't making anyone better," a Western Conference scout said. "I put that on them."

THE FRUSTRATION ON Smart's face was clear through his face mask.

"I would just like to play basketball," Smart said on Nov. 1, after the Celtics had entered the fourth quarter at TD Garden with a 14-point lead over the Bulls, only to lose by that same margin after being outscored 39-11 over the final 12 minutes.

"Every team knows we are trying to go to Jayson and Jaylen, and every team is programmed and studies to stop Jayson and Jaylen. I think everybody's scouting report is to make those guys try to pass the ball. They don't want to pass the ball ...

"They're still learning, and we're proud of the progress they are making, but they are going to have to make another step and find ways to not only create for themselves but create for others on this team."

Smart's comments led to a players-only meeting in Orlando, Florida, the following day. And though Boston's eight wins in its 11 games since then have calmed things down, these issues aren't exactly a new story in Boston.

Smart shouted at teammates in the locker room after Game 2 of the Eastern Conference finals inside the NBA's Orlando bubble a little over a year ago. Hayward never quite regained his pre-injury form and couldn't consistently stay healthy, ahead of leaving for Charlotte before last season. Irving's final season in Boston was littered with issues on and off the court, including several testy exchanges between players through the media.

"They've looked like [players that] legitimately don't enjoy each other's success, and it's been like that for years," an Eastern Conference executive said. "The fact it's still rearing its head is not surprising in that regard."

Meanwhile, Smart's critique of Tatum and Brown wasn't without merit. From the moment training camp began in late September, the Celtics have preached the importance of the duo as playmakers. So far, it hasn't happened.

Their assist numbers have dropped since last season -- from 4.3 to 3.5 for Tatum and from 3.4 to 2.5 for Brown. Both players also have seen their potential assists drop, per Second Spectrum's player tracking data, with Brown dropping from 5.4 to 4.7 and Tatum going from 8.1 to 7.6 per game. And while Brown has spent half the season sidelined with injuries, Tatum's play has drawn scrutiny from opposing teams.

"I don't think he cares about winning now, and if he does, it is on his terms. He doesn't want to score 15 and win. He wants to score 39 and win." An Eastern Conference assistant coach, on Jayson Tatum

Tatum has taken the seventh-highest percentage of contested 3-pointers this season and ranks 29th in efficiency among 30 players with at least 75 isolation plays this season -- while attempting the third most in the league -- per Second Spectrum.

This all factors into the fifth-year wing's career-worst shooting percentages from the field (41.2%) and 3-point range (33.3%) this season.

"Jayson Tatum is about Jayson Tatum," an Eastern Conference assistant coach said. "I don't think he cares about winning now, and if he does, it is on his terms.

"He doesn't want to score 15 and win. He wants to score 39 and win."

But Boston's recent play has the Celtics encouraged about where things are headed -- especially after Brown returned to the lineup on Monday against the Houston Rockets after missing eight games with a hamstring strain.

"We had some turmoil early on," Smart said after the win over the Lakers. "That's part of it, just trying to figure out a way to get each other going. And we're doing it; it's coming along. Obviously, we still have a lot of work to do, but we're on the right path."

IN THE SHORT TERM, that path is one that's reliant on Boston having an elite defense, plus just enough offense. And lately, that's worked to perfection.

Over the past three weeks, Boston has the NBA's best defensive rating, as well as the third-best net rating -- trailing the league's two best teams so far, the Golden State Warriors and Phoenix Suns.

"It's a constant reminder to us that we can rely on that every night," Udoka said of Boston's defensive improvement. "Regardless of the offensive numbers, [the defense] gives us a chance every night."

While swapping Walker for Horford cost Boston a first-round pick, it cleaned up its cap sheet for future seasons, and Horford has been far better than Walker so far this season while helping the Celtics balance out their roster.

That process also has been helped by Schroder, who fell into Boston's lap on a one-year deal after his market dried up this summer, returning to the kind of form that made him a Sixth Man of the Year candidate for the Thunder two years ago.

Add it all up and it's a formula that can allow Boston to reach its projected ceiling of being able to win a playoff series this season. Anything beyond that, though, will require something more.

One path is to acquire a third star. Virtually every champion in recent years -- from the last Celtics title team to the Miami Heat, San Antonio Spurs, Warriors, Cavaliers and Bucks -- has featured a trio of stars.

"They probably need another guy," the Eastern Conference scout said. "I love Al Horford, but he's getting older. And I love Smart. But once you get past Brown and Tatum -- and especially past [Horford and Smart] -- every guy is a question mark for me.

"They're down to two legitimate stars, [and] you normally need three [to win]."

Finding that star is tricky. The recent movement of players gravitating toward signing extensions has taken free agency largely off the board when it comes to acquiring a star player. And while Boston has all of its draft picks moving forward, other teams -- the Warriors and the New York Knicks are two examples -- are better equipped to make a splash in the trade market.

Meanwhile, another path for Boston is to have Tatum and Brown continue growing their games. The Lakers won the 2020 NBA title around two stars in James and Davis. An even better comparison are the LA Clippers, who have attempted to do the same with a pair of elite wing players in Kawhi Leonard and Paul George.

Tatum and Brown, however, still have a ways to go before they can be seen in the same light as any of those four players.

"I would put it simply: Jayson and Jaylen's ability to make other players better [is crucial]," a Western Conference scout said, when asked for what the key will be for Boston to return to championship contention. "If they can't get that third guy, they have to make other players better, and they haven't shown the ability to do that yet."

Whichever path the Celtics take, returning to championship contention won't be easy. In the meantime, they're focused on trying to grow along the way.

"You expect to win every game you play," Tatum said, "but that's never the case. I think that's just part of it. I think with a new coach and a new system, we're just trying to figure it out.

"And I think as tough and as frustrating as it can be sometimes, I think it can help you in the long run, going through these bumps. It brings you more together and closer."