Boston Celtics said guard Marcus Smart will miss the game in 4 to 6 weeks after being diagnosed with a partial tear in the left abdomen oblique muscle.
An MRI scan on Wednesday showed injuries.
Smart was injured in Sunday's Boston home defeat to Orlando.
He was helped off the floor by the trainers and after colliding with Nikola Vucevic, the Magic center, he held his left hand.
Boston will play Indiana in the first round of the NBA playoffs.
The schedule for Smart's return means he will be absent from the series and the second round, if the Celtics advance.
Last season, Smart underwent thumb surgery later in the first round of the playoffs, despite initially getting six to eight weeks of recovery.