The Philadelphia 76ers' Joel Embiid will be doubtful for Game 5 against the Washington Wizards on Wednesday night, sources told ESPN's Adrian Wojnarowski.
Embiid had an MRI on his right knee Tuesday and is expected to be evaluated further Wednesday.
He suffered the knee injury after a hard fall that knocked him out of the 76ers' 122-114 Game 4 loss Monday night. The 76ers lead the series three games to one.
Embiid crashed to the floor after he was met in the air at the rim by Wizards center Robin Lopez just over seven minutes into the game. Lopez cleanly blocked the shot, but Embiid lost his balance on the way down and crashed onto his backside and instantly grimaced in pain.
He stayed in the game after a timeout and finished the first quarter but was in some discomfort, holding his lower right back area. After checking out of the game in the final seconds of the first quarter, he went to the locker room, limping slightly, and never returned.
Embiid made an impact in his time on the floor, scoring eight points with six rebounds, two assists and a steal in the first quarter. He came into the game averaging 30 points on 67% shooting in the series.
ESPN's Brian Windhorst contributed to this report.