For an unprecedented fourth straight season, the Celtics had ranked in the top five on both ends of the floor, a level of sustained excellence that had made them the heavy favourite not just to win this series, but to reach the Finals out of the Eastern Conference. Then the 76ers took Games 5 and 6. Then the star did not show up for Game 7. And for the first time in franchise history, the Celtics blew a 3-1 lead in the playoffs, losing 109-100 to Philadelphia on their own floor at TD Garden on Saturday night. The fallout was immediate, and one fan in the arena made sure Jayson Tatum heard it directly.

A video circulating from TD Garden captured the moment clearly. A Celtics fan, still in the building after the final buzzer, pointed at Tatum and unleashed: “Tatum, it’s your fault, bro. It’s your fault. Look at you sitting down… You gonna pay. You gonna f***ing pay.” The irony is hard to overlook. Tatum did not play a single minute of Game 7, ruled out less than two hours before tip-off by the Celtics’ medical staff with left knee stiffness, leaving Joe Mazzulla to field Boston’s most important game of the season without their franchise player. A fan blaming the man who was not on the court is either grief in its rawest form or a reflection of how much weight Jayson Tatum carries in this city, regardless of the circumstances.

The knee issue surfaced in Game 6, when Jayson Tatum left after 29 minutes and did not return. He described it postgame as “just a little stiff,” and said he was not overly concerned. Coach Mazzulla confirmed on a Friday call that Tatum was expected to play. But Tatum arrived at the facility on Saturday with worsening discomfort, listed as questionable, then downgraded to out at 5:45 PM EST. “He just came in today with knee discomfort, and we decided, the medical team and myself, for him not to play,” Mazzulla said. Through the six games he did play, Tatum had averaged 23.3 points, 10.7 rebounds, and 6.8 assists while shooting 47.5% from the field, the kind of production that made his absence from Game 7 feel less like a lineup decision and more like a collapse of the entire plan.

Without him, the Celtics fell into a 9-0 hole to open the game, were outscored 33-25 in the third quarter, and trailed by 18 before a furious fourth-quarter run brought them within one possession, only for their final shots to fall short. Jaylen Brown led Boston with his series average of 24.5 points, but Scheierman, Harper, and Garza combined to go 0-for-7 from deep, and the jump-shooting team that had ranked among the best in the league all season suddenly could not convert when it mattered most. The fan’s frustration is understandable, even if the target is wrong. The defeat was a team failure. The most painful part is that the team’s best player never got to be part of it.

What’s Next for Tatum and the Celtics

The immediate question surrounding JT is medical, not basketball. Mazzulla confirmed postgame that the stiffness was located in the back of Tatum’s knee, a different area from his previous injury, and that his status moving forward would be day-to-day. The context behind that cautious approach is impossible to separate from last year. The former Duke star ruptured his right Achilles tendon against the Knicks in the 2025 playoffs and missed the vast majority of this season recovering.

He only returned on March 6 and played just 16 regular-season games before the postseason began. A second serious lower-body injury in back-to-back postseasons would be a franchise-altering development, and the Celtics’ medical staff were clearly unwilling to take any risk with a left knee problem developing in the same window. Physical therapist Dr. Evan Jeffries noted in the lead-up to Game 7 that any calf involvement carries an inherent Achilles risk. 

The broader picture for the franchise is one of a crossroads. This was Joe Mazzulla’s earliest exit as Celtics coach, and the first time Boston failed to reach the conference semifinals in a decade. Four rotation players departed last summer, and with the team still producing a top-five ranking on both ends of the floor, the expectation was that the window remained wide open.

The 76ers, meanwhile, advance as the first seven-seed to eliminate a two-seed since the playoffs expanded to a best-of-seven format in 2003, and the first team in NBA history to overcome a 3-1 deficit after entering that scenario 0-18 all-time. Boston’s collapse is the footnote on the wrong side of both records. If Tatum’s knee proves to be minor and the core remains intact, the argument will be that this is a blip in a dynasty-level run. If this summer triggers a rethink of the roster, the staff, or the timeline, Saturday night at TD Garden will be remembered as the night the Celtics’ era began to fracture.