TOKYO — Simone Biles, who withdrew from the women’s gymnastics team competition Tuesday to focus on mental health issues that dented her confidence in her ability to perform the difficult moves that have defined her brilliant career, will not compete in the women’s all-around event final Thursday.

USA Gymnastics, the sport’s national governing body, announced Biles’ withdrawal from the all-around event in a statement released mid-afternoon Wednesday in Tokyo. Biles won the all-around gold medal at Rio in 2016 and had been favored to become the first woman to win back-to-back Olympic all-around championships since Vera Caslavska in 1968.