Former UFC light heavyweight champion Rashad Evans will miss the majority of 2014 after having knee surgery this week.

Evans injured his leg during a training session ahead of his planned UFC 170 fight with Daniel Cormier this weekend. The former Ultimate Fighter winner is expected to be sidelined from active training for six months.

“I am deeply disappointed to be missing the action at UFC 170, but I am, as always, incredibly grateful for the support of my family, friends, management, the UFC, and most of all my fans during this minor setback,” said Evans, in a statement released by his team. “Thank you for your continued messages of support. I’ll be back stronger than ever!”

Ronald S. Kvitne will be performing the operation. Kvitne is the team physician for both the Los Angeles Kings and Los Angeles Blades.

Evans was replaced by Patrick Cummins in order to keep Cormier on the card. Cormier is making his light heavyweight debut.