TOKYO 2020: Biles's Olympics hanging by a thread after withdrawing from vault and uneven bars finals

Gymnastics superstar Simone Biles further slashed her Tokyo Olympics schedule over a crippling mental block on Saturday. Biles, the four-time Olympic champion widely considered the best that gymnastics has seen, dropped another two events after earlier pulling out of the team competition and the women's all-around.

The 24-year-old is struggling with the "twisties", a temporary condition where gymnasts lose the ability to orientate themselves in mid-air.

After withdrawing from the vault and uneven bars on Saturday, she has just two events left on her schedule: the floor on Monday and the beam on Tuesday. USA Gymnastics announced that their best competitor will have to take a break.

"After further consultation with medical staff, Simone Biles has decided to withdraw from the event finals for vault and the uneven bars. We remain in awe of Simone, who continues to handle this situation with courage and grace, and all of the athletes who have stepped up during these unexpected circumstances."

Biles scored her lowest Olympic vault score in the opening rotation before withdrawing from the team final. She left the arena but returned to support her teammates as the defending champions claimed silver behind Russia.

Team silver in Tokyo was Biles' sixth Olympic medal and took her tally of Olympic and World Championship medals to 30.