Mark Ballas injures shoulder before 'Dancing With The Stars' finale

LOS ANGELES (KABC) -- "Dancing With The Stars" pro Mark Ballas was seriously injured Sunday when his shoulder popped out while rehearsing his freestyle routine with celebrity partner Candace Cameron Bure.

His injury occurred just hours before the first of a two-night finale.

Ballas, 27, dropped to the floor, clutching his shoulder in pain after attempting to lift Bure. He was transported to a local hospital and released hours later.

He returned to the "Dancing With The Stars" set with his arm in a sling, according to ABC News.

Pro dancer Derek Hough, whose partner is Amy Purdy, told ABC News: "I'm not sure exactly what happened but I think it kind of came out and went back in. What makes me nervous a little bit is that he's had a serious shoulder surgery before, on the other shoulder."

Ballas will be hitting the dance floor on Monday's season 18 finale. Earlier in the afternoon, it was unclear whether Ballas would be able to compete, but ABC tweeted the good news just before 5:30 p.m. PT.

Ballas and Bure are one of four couples left in the competition. The three other couples vying for the trophy include Meryl Davis and Maksim Chmerkovskiy, Amy Purdy and Derek Hough and James Maslow and Peta Murgatroyd.

The first of a two-night finale begins at 8 p.m. Monday on ABC7.

ABC News contributed to this report.