Philadelphia 76ers center Montrezl Harrell tore his ACL and his meniscus during offseason workouts this summer and is now out indefinitely, The Athletic’s Shams Charania reported Wednesday.

Harrell underwent an MRI on Wednesday to assess recent swelling in his right knee, something that apparently popped up after offseason workouts. That MRI then revealed the torn ACL and meniscus.

It's not clear how Harrell injured his knee.

Though there is not yet a timeline for his return, considering it's an ACL injury, Harrell will more than likely miss the upcoming season.

Harrell, who signed a one-year, $2.8 million deal with the 76ers last month, averaged 5.6 points and 2.8 rebounds off the bench last season in Philadelphia. Outside of his rookie season, those were both career-lows. The 29-year-old was first selected in the second round of the draft by the Houston Rockets in 2015. He spent time with both the Los Angeles Clippers and Lakers, the Washington Wizards and Charlotte Hornets before landing in Philadelphia last season.

The 76ers fell in the Eastern Conference semifinals for a third straight time last season, which led to the organization firing coach Doc Rivers after three seasons. The team has since hired former Toronto Raptors coach Nick Nurse, who was also fired after the Raptors failed to reach the playoffs. 76ers star James Harden has requested a trade out of Philadelphia, too, which has left reigning MVP Joel Embiid in an uncomfortable situation.