Four-time Olympic gold medalist Simone Biles has withdrawn from the floor exercise event final in Tokyo, USA Gymnastics announced. She will decide on the beam final, her last chance to compete, later on.

"Simone has withdrawn from the event final for floor and will make a decision on beam later this week. Either way, we’re all behind you, Simone," USA Gymnastics said. 

Biles, 24, withdrew from the team final after one rotation, followed by the individual all-around final and vault and uneven bars finals, citing concerns about her mental health. The floor final is set for Monday and beam for Tuesday.

In addition to the weight of the immense pressure to perform in Tokyo, Biles said she was dealing with a case of the "twisties," a phenomenon gymnasts experience in which they feel a disconnect between their mind and body. The issue can be extremely dangerous when hurdling through the air, as gymnasts often lose track of where the ground is and lose control of how many times they're twisting.

In qualifications, Biles became the first woman since 1992 to advance to the final in all six possible Olympic events — the team final, individual all-around final and the vault, uneven bars, balance beam and floor event finals.

Widely regarded as the greatest female gymnast of all time, Biles won five medals at the 2016 Olympics: gold in the team final, individual all-around, vault and floor finals, and bronze on beam.