KISSIMMEE, Fla. — Joel Embiid closed his eyes, rubbed his temples and pinched the bridge of his nose, that universal signal that things are messed up beyond all repair.

The 7-footer had just scored 30 points and grabbed 13 rebounds, but the Philadelphia 76ers had lost to the Boston Celtics for the third time in three games in their Eastern Conference first-round playoff series. Hope was lost long before a critical late turnover by Embiid swung the momentum and placed the 76ers on the brink of elimination. The Celtics had won the first two games comfortably and held every advantage. They were more talented, versatile, modern and cohesive. Happier, too.

Boston danced during introductions; Philadelphia trudged. Boston celebrated its highlight plays with loud shouts and high fives; Philadelphia mostly sat in silence punctuated by occasional golf claps. Boston stars Jayson Tatum and Jaylen Brown smiled and nodded throughout postgame interviews; Embiid grimaced, collected himself and pledged to put forth more effort in a lost cause.

The Celtics completed their sweep of the 76ers with a 110-106 win Sunday afternoon, dealing the knockout blow to their Atlantic Division rivals. Philadelphia went down in Game 4 with a storm of technical fouls and a scary fall for Tobias Harris, who brought the gym to complete silence with a face-first fall. There was no hiding for the 76ers, who have spent the past three years trying to outrace their problems only to compound them.

It was no surprise that the 76ers lost this series. How they lost it — the demoralizing journey, not the emphatic destination — led Philadelphia to fire embattled coach Brett Brown on Monday and raised questions about whether Embiid would be better off elsewhere. As the Celtics ascend, the regressing 76ers face the possibility that their championship window has closed for good.

Philadelphia’s bubble run at Disney World amounted to a month-long guillotine. Brown worked under constant questions about his job security, talk that grew louder with each postseason loss and culminated with an abrupt sacking. Embiid labored under lofty expectations and a heavier load without all-star teammate Ben Simmons, looking physically and mentally exhausted by the end.

Fissures between coach and superstar showed. After Game 2, Embiid said the 76ers “had to make adjustments” defensively because their drop scheme made things “too easy” for Tatum. Following Game 3, Brown pointed to Embiid’s turnover as the turning point: “There were other targets that were open; we made the wrong read, and there’s the game.”

When the sweep was complete, Embiid distanced himself from the anticipated coaching change — “I’m not the GM; I don’t make the decisions,” he said — and let General Manager Elton Brand explain why he fired Brown, who finished 221-344 (.391) in seven seasons.

“[Brown] did many positive things during his time here, developing young talent and helping position our team for three straight postseason appearances," Brand said in a statement. "Unfortunately, we fell well short of our goals this year and I believe it is best to go in a new direction. This will be an important offseason for us as we look to get back on track towards our goal of competing for an NBA championship.”

After openly shedding tears when Kawhi Leonard’s buzzer-beater brought a stunning end to the 76ers’ 2019 campaign, Embiid retreated this year into a fog of despair.

“It’s tough,” he said Friday. “It sucks. Man, it sucks when you play super hard and do everything possible to win games and you come up short. No one wants to be in this position.”

The 26-year-old, not long ago the leading candidate to challenge Giannis Antetokounmpo as the East’s top talent, was outplayed by Tatum and Brown. Simmons, his star sidekick, was missing in action because of injury. Harris and Al Horford, key supporting cast members, provided little offensive punch and presented constant fit issues.

“You’ve got to take the team you have and maximize it,” Brown said after the sweep. “I did not do that. ... The thing I found the most challenging as the season played out: Space became an enormous issue. Effectively, you had a mismatch every possession.”

Three years ago, the East’s future seemed as if it would belong to Philadelphia and Boston — twin titans of the 1980s. Embiid was an all-star at 23, Simmons at 22. The fruits of former general manager Sam Hinkie’s long-term master plan — dubbed “The Process” — seemed they would pay dividends well after his 2016 firing.

The NBA’s tectonic plates shift quickly, though, and the ground moved under Philadelphia. The game became faster, higher-scoring and more reliant upon perimeter shooting and playmaking wings — trends that all work against Embiid and the 76ers. Even the notion of a decade-long “Process” seems antiquated in 2020, with superstars regularly changing markets and title contenders rising and falling in as few as two years.

The exciting prospect of painting on a blank canvas around Embiid and Simmons produced a clogged salary cap and a veteran core that couldn’t deliver a deep playoff run. Harris isn’t a postseason performer, and the 34-year-old Horford is years into age-related decline. Their monster contracts — five years, $180 million for Harris and four years, $109 million for Horford — will be nearly impossible to move without attaching assets Philadelphia can’t afford to lose.

The 76ers boxed themselves into a corner at Embiid’s expense, and the top candidates to replace Brown, including Los Angeles Clippers assistant Tyronn Lue, would inherit a roster heavy on size and short on versatility and shooting.

Embiid is not blameless: His injury issues, conditioning questions, loose shot selection and decision-making remain concerning. During his six years in Philadelphia, he has realized a considerable amount of his potential but hasn’t reached the conference finals or taken the league by storm. The honeymoon is over, and he seems to understand that his reputation is undergoing a market correction.

“I don’t want to be swept,” Embiid said before Game 4. “I don’t want that in my résumé.”

Ultimately, it was beyond his control. The Milwaukee Bucks, Toronto Raptors and Celtics seem fixed above the 76ers in the conference’s power rankings, and that’s before Kevin Durant and Kyrie Irving return for the Brooklyn Nets. Philadelphia, even with a healthy Simmons, finds itself discarded to the East’s second tier.

The whole point of Hinkie’s grandiose vision was to avoid this mediocrity, yet here they are anyway. Brand has plenty to answer for, and ownership should think hard about whether to bring him back. The first-time executive made a terrible trade for Harris, incorrectly chose Harris over Jimmy Butler and vastly overpaid for him. He then signed Horford, a decision that looked reasonable at the time but didn’t pay dividends.

To see Embiid and the 76ers this week was to be reminded of Russell Westbrook and the Oklahoma City Thunder last year. Both stars have been synonymous with their cities, both hit walls in the playoffs, and both endured the lion’s share of the criticism for their organization’s shortcomings. But Westbrook unexpectedly found an escape hatch to the Houston Rockets, where his second chapter has freed him from aggravating narratives and pent-up frustration.

When Embiid closed his eyes and pinched his nose Friday, he was hoping to will away another question from a reporter because the real answers are out of his control. He wore his agony of defeat just as Westbrook used to sport a steely stare after playoff losses.

The biggest difference is that the Thunder empowered Westbrook, positioning him to become an MVP, supporting his triple-double obsession and swinging for the fences to get Paul George after Durant departed.

Philadelphia, by contrast, has not held up its end of the bargain with Embiid, whose relationship with the front office has at times been rocky. Former GM Bryan Colangelo was let go in 2018 after an anonymous Twitter account linked to his wife had posted insulting messages about Embiid, calling him “lazy” and “selfish.” Then, in March, 76ers employees’ salaries were set to be reduced during the novel coronavirus shutdown, prompting Embiid to pledge to provide financial assistance; ownership, under heavy public pressure, reversed course.

With his bubble stay complete, Embiid should ponder the lessons of Westbrook’s offseason relocation. It doesn’t have to be like this forever, and there’s no shame in pursuing an exit strategy.

“I always say that I want to end my career here,” Embiid said. “If it happens, good. If it doesn’t happen, well, you move on and all that stuff.”