The former Duke star had to be helped off the court.
Milwaukee Bucks young forward Jabari Parker suffered a knee injury during his team's loss to the Miami Heat on Wednesday night.
Parker's knee appeared to buckle while he was driving to the basket.
Here's the video:
Parker suffered a torn ACL during the 2014 season.
The Bucks said Parker left Wednesday night's game with a sprained knee. He will reportedly have an MRI on his knee today.
Parker, 21, is averaging 20 points and six rebounds this season.