The Boston Celtics may have to advance to the Eastern Conference Finals without the heart and soul that is Marcus Smart.

The injury was first reported by ESPN’s Adrian Wojnarowski shortly before 7 p.m., with Woj noting that it was a ‘torn’ left oblique for the 25-year-old Smart, and that Smart would likely miss the first two rounds of the postseason.

The Celtics, meanwhile, went for a more medical description of the ailment.

According to the Celtics, an MRI revealed that Smart suffered a partial avulsion of his left oblique abdominal muscle off of his iliac crest. (Yeah, same.) The injury occurred at 6:44 in the third quarter of Sunday’s game against Orlando, following contact with the Magic’s Nikola Vucevic.

Smart is currently expected to return to basketball activities in four to six weeks, according to the team.

The Celtics, meanwhile, will begin their first-round series with the Indiana Pacers this weekend.