Nets guard Jeremy Lin had to be helped to the locker room Wednesday against the Pacers.
The 29-year-old went up for a layup on a fast break, but came down awkwardly on his right knee.
"I'm done man," he was heard saying. "I'm done, I'm done."
The Nets have not announced the nature of Lin's injury. He had 18 points and four assists before going down.
ESPN reported there is tremendous concern over his knee in the organization. Lin, who missed 46 games last season, will be evaluated in New York on Thursday.