"I'm so disappointed for Theo," UNC coach Roy Williams said in a statement. "No. 1, he's been playing well and he does so many positive things for our team. Theo's our energy guy, he defends, he's our best passer, a threat on the offensive boards, he can play four different positions, and he gives our team personality, and I mean that in a good way.
"Hopefully we can get him back before the end of the season, but we have not met with all the medical personnel yet so there is no timetable for when he can play again."
The 6-foot-6 Pinson fractured the fifth metatarsal in his right foot. During his freshman season, he missed 10 games after breaking the same bone in his left foot.
Pinson spoke of his disappointment from his freshman year injury during the Tar Heels media day this month.
"It brought me down a little bit. It was my second time doing it," Pinson told ESPN.com on Oct. 11. "I feel like I was just starting to get it my freshman year and then it was a big step back. You can't go for that long then come back and play in our system because we're going up and down, everything is happening so fast."
Pinson was expected to compete for a starting spot at guard. Last season, he replaced an injured Marcus Paige and started the first six games. Pinson appeared in all of Carolina's 40 games last season, averaging 4.5 points per game and was third on the team with 115 assists.