Celtics start season amid roster overhaul after Tatum injury

With the regular season set to begin Wednesday night at TD Garden, the Boston Celtics will open a campaign of deep renovation and uncertainty after a turbulent offseason that followed Jayson Tatum’s ruptured Achilles in May. The team trimmed payroll aggressively, sent several veterans elsewhere and has adopted a markedly different style under coach Joe Mazzulla, while All Star Jaylen Brown’s availability for opening night is uncertain because of a hamstring issue. Separately, veteran guard Malcolm Brogdon announced his retirement this week, removing another experienced hand from the league.

Tatum’s offseason injury forced the Celtics into a broader reset that accelerated plans already in motion to get under the NBA’s so‑called second apron, front office leaders and former executives said. That financial constraint contributed to trades that moved Jrue Holiday and Kristaps Porziņģis and to the departures in free agency of Al Horford and Luke Kornet. Brad Stevens, the team’s president of basketball operations, described the moves as painful but necessary to restore roster flexibility and avoid long‑term cap penalties.

Mazzulla has responded by reshaping Boston’s on‑court identity....