Sources: Cain Velasquez off UFC 207 card as NSAC won't OK fighter

— -- A heavyweight rematch between Cain Velasquez and Fabricio Werdum scheduled for next week's UFC 207 event in Las Vegas has been canceled, according to sources.

The Nevada State Athletic Commission opted to not approve Velasquez (14-2) to compete, due to medical issues. The UFC did not immediately respond to a request for comment.

Earlier this week, Velasquez, 34, told ESPN.com he had suffered from back pain during training camp and was already scheduled to undergo surgery on Jan. 4. The San Jose-based heavyweight said he had relied on Cannabidiol (CBD) to dull the pain enough to train.

"It's an achy pain that goes down your leg, and it gets to a point where if you're standing for 10 minutes, you have to sit down," Velasquez told ESPN.com. "If you're going out for a while, a half-hour, you know it's going to be pretty painful. You have to sit down and take the compression off your back."

Despite those revelations, both Velasquez and his longtime coach Javier Mendez insisted he would be fine to face Werdum. The fight was supposed to be a rematch of a heavyweight title fight that took place in June 2015.

"As far as preparation, I've done everything," Velasquez said. "I've sparred, wrestled. I'm not missing workouts at all. I've done my conditioning -- everything. I feel great going into this."

According to sources, the NSAC still felt due to Velasquez's comments regarding the injury, a decision was made to cancel the bout for fighter safety.