The Boston Celtics are staring down the barrel of a historic collapse, and head coach Joe Mazzulla is once again under the microscope for his postseason adjustments—or lack thereof.
After a brutal Game 6 loss to the Philadelphia 76ers on Thursday night, the Celtics saw their 3-1 series lead evaporate, forcing a win-or-go-home Game 7 on Saturday. If they fall, they'll join an unfortunate club: just the 14th team in NBA history to lose a series after holding a commanding 3-1 advantage.
For a squad that entered the 2026 season with championship aspirations, this is not the script anyone in Boston envisioned.
The issues in Game 6 were painfully familiar. Jaylen Brown played with reckless abandon, forcing shots and turning the ball over. The starting unit—a group that has been a net negative throughout the series—looked sluggish and disjointed on offense. Meanwhile, Boston's top two big men offered virtually no scoring punch. It was, in many ways, a carbon copy of the Game 5 meltdown.
Yet Mazzulla stuck with the same rotation until the game was well out of reach, only pulling his starters in the fourth quarter to rest them for the do-or-die Game 7. No major lineup shakeup. No small-ball experiment. No spark off the bench.
This has become a troubling pattern for the Celtics' head coach. Last season, he famously stuck with Kristaps Porzingis for far too long in a playoff series, refusing to pivot even as the matchup soured. Now, with a deep and versatile roster at his disposal—one that allowed him to mix and match lineups all regular season—Mazzulla has reverted to old habits when it matters most.
Sam Hauser has struggled to find his rhythm, yet Jordan Walsh or Baylor Scheierman remain glued to the bench. Nikola Vucevic has been a liability on both ends of the floor, but still logged his usual minutes. And despite the success of small-ball lineups during the regular season, Mazzulla has yet to deploy them in this series.
For a team that prides itself on depth and adaptability, the Celtics are suddenly looking rigid—and their season hangs in the balance because of it.
Game 7 tips off Saturday night in Philadelphia, with the over/under set at 205.5 points. For Boston, it's simple: adapt or go home.