Jonas Valanciunas was taken to a Chicago hospital as a precaution following a 'whiplash-like' injury at the end of the Toronto Raptors' 101-98 win over the Bulls.
Valanciunas banged his head into Rudy Gay's shoulder while going for the ball out of a jump ball.
Play was not stopped, but Valanciunas went straight to the Raptors' bench to sit on one of the chairs.
Valanciunas was fitted with a protective collar and escorted from the court.
Valanciunas was kept overnight at the hospital for observation.