Phil “CM Punk” Brook’s UFC debut is delayed for back surgery.

The former WWE champion turned MMA fighter is scheduled to undergo back surgery in Chicago on Wednesday due to a herniated disc, has learned.

Punk, née Phil Brooks, has been battling a lingering back injury from his years as a professional wrestler. Recently, the injury worsened.

“My back has always bugged me,” Punk told “Figured it was just wrestling sh*t. Turns out it was.

“It got bad enough to the point where I couldn’t do anything the week before I went to train with the New Jersey Devils last month. One day I could manage, the next day I couldn’t. I’ve been in agony for almost a month. Chiropractor, acupuncture, massage, cryotherapy … nothing worked.”

On Saturday, Punk learned that he would be facing 24-year-old Mickey Gall in his debut after Gall defeated fellow UFC newcomer Mike Jackson via first-round rear-naked choke. Coincidentally for Punk, he was advised by his doctor right before the fight that he needed surgery, but Punk decided to keep that news for himself.

Punk announced that he had signed with the UFC in Dec. 2014. A shoulder injury this summer delayed his debut, but the UFC had recently announced that the plan was for him to make his highly-anticipated Octagon debut this summer. While those plans will change now, Punk’s recovery post-surgery is expected to be four-to-six weeks so his intention is still to fight at least once in 2016. Punk noted his injury and surgery is very similar to the one former UFC heavyweight champion Cain Velasquez underwent last week.

“This is just a bump in the road,” he said. “I’m positive about this.”