Jason Genet, the manager for Shane Carwin, informed Fighters.com that his client suffered extensive damage to his knee in training.

Carwin was forced to withdraw from a planned heavyweight encounter with Roy Nelson next month at The Ultimate Fighter 16 Finale. A replacement fighter for Carwin is being sought, as the two are currently seen as coaches on The Ultimate Fighter.

“He was essentially training through the injury and pushed too hard, too fast,” said Genet, who confirmed that Carwin tore his PCL, LCL and popliteus. “The gut feeling is that he can recover without surgery if he rehabs it.”

Carwin made mention of a knee injury several weeks back, but claimed he would be able to fight through it and remain on track to compete. The former interim UFC heavyweight champion was looking to return to action for the first time since a 2011 loss to Junior dos Santos.