Simone Biles abandoned the defence of her individual all-around Olympic crown on Wednesday, a day after her shock withdrawal from the women’s team final over mental health concerns.

As a worldwide outpouring of support for the troubled US gymnastics superstar grew, a statement from USA Gymnastics confirmed that Biles would not take part in Thursday’s all-around final.

The 24-year-old 2016 Olympic all-around gold medallist’s participation in the four individual event finals starting on Sunday will be decided after further evaluation, USAG said.

“Simone Biles has withdrawn from the final individual all-around competition at the Tokyo Olympic Games in order to focus on her mental health,” USAG said in a statement.

“Simone will continue to be evaluated daily to determine whether or not to participate in next week’s individual event finals. We wholeheartedly support Simone’s decision and applaud her bravery in prioritising her well-being. Her courage shows, yet again, why she is a role model for so money.”

Olympic athletes are human, doing the best: Reactions to Simone Biles pulling out of team event

The decision marks a stunning turn of events for Biles, who had been widely expected to crown the greatest career in gymnastics history with another multiple haul of gold medals in Tokyo.

The diminutive Texan, winner of four gold medals at the 2016 Rio Olympics, was vying for a potential six golds in Japan.

Game-changing moment

However her campaign unraveled on Tuesday when she suddenly withdrew from the team final after an uncharacteristically shaky display on the opening vault. Biles later said she had pulled out of the final out of concern for her mental well-being.

“I have to focus on my mental health,” Biles said. “I didn’t want to go out and do something stupid and get hurt... At the end of the day we don’t want to be carried out of there on a stretcher.”

Biles’ decision has been hailed as a game-changing moment for elite sport, helping to dispel enduring stigmas surrounding mental health.