'Biggest Loser': Anna Kournikova Replacing Jillian Michaels

The tennis star will join the weight-loss competition as a celebrity trainer for its upcoming 12th season.

Tennis star Anna Kournikova is set to replace Jillian Michaels as the celebrity trainer on The Biggest Loser.

NBC made the announcement Tuesday night during the live finale of the reality show, during which the Russian native made an appearance.

The move is just one of several changes reportedly in store for the weight-loss competition, as trainers Brett Hoebel and Cara Castronuova are also said to be exiting the show.

Michaels announced last year that the current season -- the show's 11th -- would be her last.