Holly Madison, Melissa Rycroft join 'Dancing'

LOS ANGELES -- Hugh Hefner's ex-girlfriend Holly Madison and "The Bachelor" reject Melissa Rycroft are joining "Dancing With the Stars."

The two reality TV stars replaced injured contestants Jewel and Nancy O'Dell, who dropped out of the competition last week.

Madison, a star of "The Girls Next Door" and four-time Playboy cover model, replaced Jewel on Monday's season premiere. She spent five days rehearsing with Jewel's former professional partner, Dmitry Chaplin.

Rycroft joined the cast just three days ago. Host Tom Bergeron said that makes her "the performer with the least amount of training in the history of the show."