American tennis phenom Coco Gauff will no longer compete at the Tokyo Olympics after testing positive for COVID-19, she announced on Twitter Saturday.

“I am so disappointed to share the news that I have tested positive for COVID and won’t be able to play at the Olympic Games in Tokyo,” the 17-year-old wrote. “It has always been a dream of mine to represent USA at the Olympics, and I hope there will be many more chances for me to make this dream come true in the future. I want to wish TEAM USA best of luck and a safe games for every Olympian and the entire Olympic family.”

After making it to the quarterfinals at Wimbledon in June, Gauff was the headliner on a United States roster that was ravaged by big-name opt-outs. On the women’s side, top-ranked women Serena Williams and Sofia Kenin declined their invites to the Games, and on the men’s side, the top three — John Isner, Reilly Opelka and Taylor Fritz — opted out.