Four-time Olympic gold medalist Simone Biles withdrew from the team competition Tuesday, opening the door for Russia to upset the United States and win the gold medal at the Tokyo Olympics.

The last time the U.S. women did not win the team competition in the Olympics was the 2008 Games in Beijing.

USA Gymnastics said in a statement that Biles, 24, withdrew from the team final “due to a medical issue. She will be assessed daily to determine medical clearance for future competitions.”

Following the event, Biles teared up as she told reporters her withdrawal from Tuesday’s competition was to prioritize her health and protect her team.

“I didn’t want to go into any of the other events second-guessing myself,” Biles told reporters. “So, I thought it would be better if I took a step back and let these girls go out there and do their job.”

“I just don’t trust myself as much as I used to, and I don’t know if it’s age. I’m a little bit more nervous when I do gymnastics,” Biles added. “It just sucks that it happens here at the Olympics Games… But, you know, with the year that it’s been, I’m really not surprised the way it played out.”

Biles withdrew from the team final after struggling on the vault, where she posted an uncharacteristically low score and didn’t stick her landing.

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Following the stumble, Biles was seen with team doctor Marcia Fausti before leaving the floor with a trainer. She returned a short while later wearing a sweatsuit, and continued to root on her teammates.

Biles’ teammates — Suni Lee, Grace McCallum, and Jordan Chiles — finished out the competition, earning a silver medal for the United States. Great Britain edged out Italy for the bronze.

Eight countries were competing in the team gymnastics final, with each team fielding three gymnasts on each of the four events — vault, uneven bars, balance beam, and floor exercise.

It’s not clear if Biles will compete in the women’s gymnastics all-around final, which is scheduled for Thursday. Biles won the gold in both the individual all-around and the team event in the 2016 Olympics in Rio de Janeiro.

Biles also qualified for all four gymnastics event finals, which begin Sunday.

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