Portland Trail Blazers guard CJ McCollum left Saturday night's game in San Antonio after injuring his left leg during a drive to the basket.
McCollum crashed to the court with 7:17 left in the third quarter and immediately grabbed his knee in apparent pain.
Team-mates Skal Labissiere and Meyers Leonard helped him to the locker room.
The team called it a left leg injury and McCollum did not return to the game.
ESPN's Adrian Wojnarowski reported that McCollum will undergo an MRI on his left knee on Sunday.
The sixth-year veteran entered Saturday's game against the Spurs averaging 21.5 points, 4.1 rebounds and 2.9 assists in 67 games (all starts).
He scored 10 points on 5-of-13 shooting and added five assists in 23 minutes before the injury.