Jimmy Butler suffered a knee injury during Wednesday night's 105-104 loss to the Philadelphia 76ers in the Play-In Tournament.
The veteran forward—who finished with 19 points, five assists, five steals and four rebounds but shot just 5-of-18 from the field—told reporters after the game that he would undergo an MRI on Thursday.
"It had me feeling that I couldn't do too much," he added of the injury.
The Athletic and Stadium's Shams Charania reported after the game that Butler "is feared to have an MCL injury in his knee" that could sideline him "for an indefinite period.