Orlando Magic forward Jonathan Isaac suffered a hyperextended left knee during Wednesday's game at Washington, the team announced.
He will undergo an MRI on Thursday in Orlando and then be re-evaluated.
Isaac's legs got tangled as he drove to the basket at 9:57 of the first quarter and he crumpled to the floor, clutching his knee. He was taken off the court on a stretcher.
Isaac is in his third season with the Magic after being selected sixth overall in the 2017 NBA draft out of Florida State.
He went into Wednesday's game averaging 12.3 points and 7.1 rebounds.