Naomi Osaka withdrew from the French Open on Monday and wrote on Twitter that she would be taking a break from competition, a dramatic turn of events for a four-time Grand Slam champion who said she experiences “huge waves of anxiety” before speaking to the media and revealed she has “suffered long bouts of depression.”

Osaka is No. 2 in the world rankings.

The stunning move came a day after Osaka, a 23-year-old who was born in Japan and moved with her family to the U.S. at age 3, was fined $15,000 for skipping the postmatch news conference after her first-round victory at the French Open. She also was threatened by all four Grand Slam tournaments with possible additional punishment, including disqualification or suspension, if she continued with her intention — which Osaka revealed last week on Twitter — to not “do any press during Roland Garros.”

She framed the matter as a mental health issue, saying that it can create self-doubt to have to answer questions after a loss.

“First and foremost we are sorry and sad for Naomi Osaka. The outcome of Naomi withdrawing from Roland Garros is unfortunate,” French tennis federation president Gilles Moretton said Monday. “We wish her the best and the quickest possible recovery. And we look forward to having Naomi in our tournament next year.”

Moretton said the four major tournaments, and the professional tennis tours, “remain very committed to all athletes’ well-being and to continually improving every aspect of players’ experience in our tournament, including with the media, like we always have.”

In Monday’s post, Osaka spoke about dealing with depression since the 2018 U.S. Open, which she won by beating Serena Williams in a final filled with controversy.

“I would never trivialize mental health or use the term lightly,” Osaka wrote, explaining that speaking with the media makes her anxious.

“I think now the best thing for the tournament, the other players and my well-being is that I withdraw so that everyone can get back to focusing on the tennis going on in Paris,” Osaka wrote. “I never wanted to be a distraction and I accept that my timing was not ideal and my message could have been clearer.”