Jayson Tatum Hit the Gym with Joe Mazzulla in Vegas and It Tells You Everything About Boston’s Plan

Jayson Tatum is in Las Vegas for Summer League, but he’s not just watching from a courtside seat. He’s working.

The Celtics star forward was spotted running drills with head coach Joe Mazzulla in a gym out in Vegas this week, and the video made the rounds fast. It’s the kind of footage that doesn’t mean much on its own — players work out all summer — but in context, it’s a signal. This is Tatum’s team now. For real.

Boston traded Jaylen Brown to Philadelphia for Paul George and some draft picks earlier this offseason. That move didn’t just reshape the roster. It changed the entire identity of the franchise. For a decade, the Celtics ran a two-star system. Now it’s Tatum alone at the top, with George as the high-level second option and a supporting cast that still has questions.

Tatum is coming off an injury-shortened season. He tore his Achilles in the 2025 playoffs and spent most of last year rehabbing. He got back on the floor late in the regular season and played 16 games, averaging 21.8 points, 10 rebounds and 5.3 assists. In the playoffs, those numbers jumped to 23.3 points, 10.7 boards and 6.8 assists. But Boston still lost in the first round, blowing a 3-1 series lead to the 76ers. The same team that now has Jaylen Brown.

So yeah. There’s motivation.

Tatum looked good in the minutes he got last season. His burst wasn’t all the way back — that kind of injury takes time — but he was still clearly a superstar-level player. A full offseason of work, with no rehab schedule to manage, changes everything. He’s been around the Summer League team in Vegas, getting up shots, staying engaged. The workout with Mazzulla is just the latest sign that he’s locked in.

What the Celtics need from Tatum this season

Boston finished 56-26 last year, which was better than anyone expected given Tatum missed most of the season. That’s a credit to the depth and to Mazzulla’s coaching. But the ceiling on this team is decided by one guy. If Tatum is healthy and playing at his MVP-level peak, the Celtics are contenders. If he’s still working his way back, they’re a dangerous second-round team at best.

Paul George helps. He’s 36 and has his own injury history, but he’s still a two-way difference-maker when he’s on the floor. The Celtics also added some young pieces in the draft and have cap flexibility to make more moves in free agency. But nobody in that front office is pretending this roster is complete.

There’s pressure here. Tatum is entering Year 10. He’s got the resume — All-NBA selections, Finals appearances, Olympic gold. But the post-Brown era starts now, and the clock is ticking on Boston’s championship window. Working out with your head coach in Vegas in July doesn’t win you a title. But it’s a start.