It might be some time before Derek Hough can dance again.

The Dancing With the Stars pro, who was partnered with Olympian Shawn Johnson for the show's All Star season, aggravated a pre-existing neck injury during the program's October 30 broadcast.

"I have a bulging disc on my vertebrae," he explained to Us Weekly as he iced his neck post-show. "I've had it for a couple years. I need surgery on it. It flares up and it did today unfortunately. It immobilizes me but we dance through it on adrenaline."

The pain was too much to push through Monday night, however.

"Derek's injury is really serious," a show insider tells Us, explaining that Hough will not be dancing Monday. (Mark Ballas is slated to fill in for him, instead).

In fact, the choreographer's condition is so severe, "It's likely Mark will finish out the season for him."

Adds the insider, "Derek is so disappointed but very badly hurt. He needs surgery."

This article originally appeared on Usmagazine.com: Injured Dancing With the Stars Pro Derek Hough Might Not Return This Season