Simone Biles will not defend her gold medal in the individual all-around event, USA Gymnastics announced.
The NBC broadcast first broke the news, saying the four-time gold medalist has withdrawn from the event in order to focus on her mental health.
The decision comes after Biles withdrew during the opening routine of the team gymnastics finals on Tuesday. Biles won the 2016 event in Rio, becoming the fourth straight American woman to win the individual all-around.
"After further medical evaluation, Simone Biles has withdrawn from the final individual all-around competition," USA Gymnastics said in a statement.