Celtics-76ers rivalry gets its dates — and the Brown-Tatum feud is the NBA's hottest storyline

The Boston Celtics knew the 2026-27 schedule would come with questions. They just didn't know how loud they'd be. With all four Celtics-76ers regular-season matchups now officially on the calendar, the league's newest and most personal rivalry has its stage — headlined by Jaylen Brown's return(s) to Boston.

The tension began in May, when the 76ers knocked the Celtics out of the playoffs in five games, taking the decisive contest at TD Garden. It escalated in July when Boston traded Brown, a ten-year franchise cornerstone, to that same Atlantic Division rival. And it boiled over this week at Brown's introductory press conference in Philadelphia.

Brown didn't hold back. He admitted he "threw my phone across the room" when he learned of the trade, told reporters he's "not really" talked with Jayson Tatum since the deal, and said he felt "disrespected" and "more inspired to win." He also called playing alongside his new teammate LeBron James "what an opportunity that is." Within minutes, the quotes reignited a feud that had simmered all summer.

For Boston, the Brown trade remains the defining move of the offseason. In exchange, the Celtics brought back Paul George, a veteran wing who — while no longer the All-NBA force Brown is — gives Tatum a proven second option. The Athletic's recent roster breakdown suggested Boston's new-look bench may boast more depth than initially expected, even if the wing star power took a hit.

That depth matters. The Celtics still project as one of the East's top teams. They finished 2025 at 56-26 — the best record in the Atlantic — and posted a 7.51 net rating with a stout 109.75 defensive rating, per team comparison data. Their offense graded out at 117.3 points per 100 possessions. For the upcoming season, sportsbooks have set Boston's win total at 51.5, a number that reflects both respect for the returning core and the uncertainty of life after Brown.

Tatum, meanwhile, is positioned for a monster campaign. With Brown gone, the offense runs entirely through him, and his MVP odds sit at +2500 — roughly a 3.9% implied probability. His career splits — 23.8 points, 7.6 rebounds, and 4.1 assists per game — suggest those numbers could climb with the ball in his hands more than ever.

The real fireworks come on the court. Four regular-season meetings. Two former co-stars who aren't on speaking terms. A franchise that chose to build around one star. And a 76ers squad that believes it stole one of the East's best players from a division rival. Every matchup will carry playoff-level intensity.

The Celtics' defense remains elite, and they out-rebounded opponents at a strong 46.4 boards per game. But Philadelphia now pairs Brown with LeBron, plays at a faster pace (101.3), and swipes 8.69 steals per game — a disruptive combination that could trouble Boston's offense. Brown knows the Celtics' sets as well as anyone alive.

The question isn't whether the Celtics can contend for the Atlantic crown — their 56-win campaign says they're right there. It's whether this new-look roster can handle the 76ers in what's shaping up to be the East's defining rivalry. The schedule is set. The storylines are loaded. And for Tatum, the league's most scrutinized star, each of those four games is now a referendum.