"Shawn and Derek (Hough) is going to be sick," he told ET in an interview while gearing up to run the New York City Marathon on November 4. "You know Derek's going to get excited -- he's like a gymnast. He's going to have her flip off the rafters or do something crazy -- then he's going to take his shirt off at some point."
Among other returning contestants J.R. thinks have a competitive chance are actor Gilles Marini, Olympic skater Apolo Anton Ohno and singer Sabrina Bryan.
Watch the video to also hear the U.S. Army veteran and actor speak about being a father and trading in his dancing shoes for running shoes to run the marathon on behalf of watchmaker Timex. J.R. -- who will be wearing a Timex GPS timepiece -- will actually start the race in last place, but for every person he passes, the company will donate $1 to the New York Road Runners Youth Program.
Be sure to catch the Dancing with the Stars: All-Stars two-night premiere beginning September 24 at 8 p.m. on ABC.