Kidd-Gilchrist had six points and three rebounds in 19 minutes Tuesday before leaving the game, and said he's not sure when he suffered the injury.
"It was [pointing] the wrong way," Kidd-Gilchrist said of the injury. "That's it.
"I was really surprised. I didn't feel anything at the time. ... It happens in this league."
Bobcats coach Steve Clifford said he didn't know how long Kidd-Gilchrist would be out.
In his second year, Kidd-Gilchrist is averaging 9.3 points and 5.4 rebounds per game for Charlotte (8-11).
"It's going to be tough to make up for what he does," Clifford said.