For Cain Velasquez, the biggest obstacle to his MMA career has been staying healthy.

The former UFC heavyweight champion was forced to pull out of a planned title rematch with Fabricio Werdum that would have taken place this coming Saturday after injuring his back.

Velasquez (13-2), who has made all but two of his pro appearances inside the Octagon, is in so much pain that he will require surgery to repair the disc in his back that is causing him fits, according to UFC president Dana White.

“Cain has got problems with a disc in his back, and he’s actually going to have surgery,” White said while appearing on a recent edition of “Opie with Jim Norton.” “The good part is it’s not going to be long. He’s going to have the surgery and will probably need four weeks to recover.

“So that’s good news.”

While the time-table for a return is shorter than maybe expected, White did not mention if Velasquez will remain in the role of top contender. Officials attempted to pair Werdum with Stipe Miocic, but the reigning champion also removed himself from the card due to a series of injuries.

During his time with the UFC, Velasquez has been sidelined numerous times. The 33-year-old former NCAA wrestler from Arizona State University fought three times in 2009 and twice the next year.

However, he’s made just a total of six appearances since, including only one fight – a June 2015 loss to Werdum – since defeating Junior dos Santos for a second time in 2013 to retain the UFC title.

The resume of Velasquez is one of the best in the division’s history, as he holds the two wins over “Cigano,” a pair of victories via first round stoppage vs. Antonio Silva, first round knockouts of Brock Lesnar and Antonio Rodrigo Nogueira, and a second round finish of Ben Rothwell.

Thanks to for transcribing the quotes.