The MMA world released a collective groan Sunday, as former heavyweight champion Cain Velasquez pulled out of his scheduled Feb. 6 title fight against Fabricio Werdum at UFC 196 with a back injury.

Velasquez – no stranger to suffering injuries and needing to pull out of fights – was replaced by Stipe Miocic at the event.

While Werdum would later pull out of the fight with an injury as well, much doubt and criticism lingers toward Velasquez and toward his camp, San Jose's American Kickboxing Academy.

UFC middleweight champion and teammate to Velasquez, Luke Rockhold, joined Ariel Helwani on Monday's edition of The MMA Hour to shed some light on the nature of Velasquez's latest setback.

"He’s had a bad back for a while now," Rockhold said. "He’s been trying to fight through it and it’s been progressively getting worse. He hasn’t been able to spar and train much. He’s been working around it, doing the best he could, but you can’t go into a fight without really training. I think he just decided to pull the plug last minute. It needed to be done. He basically got no bushings in his lower discs."

Rockhold said he didn't know whether Velasquez would require surgery for this issue, and communications have been somewhat limited between the two in the immediate aftermath.

"It’s been an unfortunate string of injuries, of course, with Cain," Rockhold said. "He’s never had great camps going forward. I haven’t talked to him. I know the situation, I know where he’s been every day. It is what it is at this point. He can’t go in there, he needs to go up and show up and get his title back and be healthy to do it. You just kind of wait, wait for the time, when the time’s right."