North Carolina freshman guard Anthony Harris went down with just more than three minutes to play in Monday night's 70-67 victory against Yale after his right knee buckled.
Harris missed the team's first eight games of the season while recovering from a torn ACL in his left knee.
"Our hopes and prayers are that there's nothing seriously wrong, but we won't know until they do all the tests and things like that,'' UNC head coach Roy Williams said after the game. "My team is hurting for him right now.''
The 6-foot-4 Harris has appeared in four games with North Carolina this season, averaging 6.0 points and 1 assist in 13 minutes.
The Associated Press contributed to this report.