ET caught up with professional dancer Mark Ballas just one day after his surgery.

"Dancing with the Stars" professional dancer MARK BALLAS surprised everybody by turning up at rehearsals on Thursday for the upcoming "Soft Scrub® Presents Dancing with the Stars -- The Tour," kicking off on December 18th, at Key Arena in Seattle, and traveling to 37 cities.

"I had the surgery yesterday, so I am feeling pretty okay to watch and be around and keep my eyes on things," Mark told ET in an exclusive interview. "I have to go to the doctor's next Tuesday, so I am just going to watch for the next couple of days. But every four hours I have to take it out of the sling [and exercise it]."

If for some reason Mark isn't able to dance, DEREK HOUGH is learning the routines and can take over as partner to SABRINA BRYAN.

"He just needs to take care of her and not be too rough with her," Mark advises Derek.

As for his dancing partner, "She has been there every step of the way," he says. "She has come to all my appointments, and she dropped me at the hospital for my surgery. When it happened on the show on a Tuesday, it happened halfway through the routine. I looked at her, and said, this is not good. She knew."