Four years ago, Naomi Osaka displayed an unexpected level of greatness with racket-in-hand at the U.S. Open by upsetting Serena Williams, 6-2, 6-4 in a penalty-marred final. But the then 20-year-old Japanese also showed a troubling level of emotional fragility, as she sobbed quietly in her chair, hid her eyes behind the beak of her cap, struggling to cope with the unpleasantness of the moment. She says the impact of that 2018 U.S. Open experience lingers still.

In Paris Tuesday, Osaka’s on-court greatness took a back seat to her emotional fragility, as she chose to withdraw from the French Open rather than attend mandatory post-match interviews with the media. “I have suffered long bouts of depression since the US Open in 2018 and I have had a really hard time coping with that,” she said in a statement.  “Anyone that knows me knows I’m introverted, and anyone that has seen me at the tournaments will notice that I’m often wearing headphones as that help dull my social anxiety.”

Four years ago, Osaka couldn’t hide her despair as she watched her idol argue vociferously with umpire Carlos Ramos who cited Williams for three code violations, after Williams led Osaka 3-1 in the second set. Williams demanded an apology from Ramos for accusing her of cheating but instead received a game penalty which gave Osaka a 5-4 lead.

“Serena hugged me, and it was really awesome,” Osaka said after capturing her first of four major titles. “I felt like a little girl. She was nice to me at the net and at the podium.”

In her written Paris statement, Osaka apologized to the journalists covering the event. “I am not a natural public speaker and I get huge waves of anxiety before I speak to the media, she said. I … find it stressful to always try to give you the best answers I can. I never wanted to be a distraction … my timing was not ideal, and my message could have been clearer. More importantly, I would never trivialize mental health or use the term lightly.

Though tennis greats Billie Jean King, Martina Navratilova and Chris Evert were among the first to condemn Osaka’s pre-tournament plan to boycott post-match interviews, they softened their criticism when Osaka her condition involved mental health issues. “These athletes are teenagers and in their early 20s,” Evert said. “They can’t cope with what a 45-year-old golfer can. The press needs to have compassion with what they ask.”

“I’m gonna take some time away from the court now, but when the time is right, I really want to work with the Tour to discuss ways we can make things better for the players, press and fans.”

Leaders of the International Tennis Federation (ITF), which governs the Grand Slam events (Australian Open, French Open, Wimbledon and U.S. Open vowed to address mental health issues. In a separate statement issued Tuesday to the Associated Press, ITF official Heather Bowler said the sport will “review what needs to evolve” after Osaka “shone a light on mental health issues.”