Anna Kournikova's The Biggest Loser training job will be ending after a single season.

Kournikova has confirmed she won't be returning to The Biggest Loser for its thirteenth season after serving as a trainer for the show's currently-airing twelfth season alongside Bob Harper and fellow new trainer Dolvett Quince.

"I enjoyed my time on The Biggest Loser ranch. Although I will not be returning as a full time trainer on season 13, I will always be a part of The Biggest Loser family and my commitment to bettering lives through health and fitness will continue," Kournikova said in a statement, obtained by The Hollywood Reporter.

According to The Reporter, The Biggest Loser staffers had issues with Kournikova, while some of the contestants found her teaching methods harsh and her attitude unsympathetic.

In addition, the former tennis star also reportedly told her contestants about the adversities she had faced in her own life instead of consoling them when they had struggled with training difficulties.

A show source told The Reporter that Kournikova was "a nightmare" and certainly not a life coach.