The 17-year-old was set to be the youngest Olympic tennis player since 2000.
Coco Gauff announced that she has withdrawn from the Tokyo Olympics after testing positive for COVID-19.
The 17-year-old was the second-highest ranked women's player in the U.S. team selected for Tokyo. Gauff is also the youngest player ranked in the WTA Tour top 100.
"I am so disappointed to share the news that I have tested positive for COVID and won't be able to play in the Olympic Games in Tokyo," Gauff wrote on Twitter.
"It has always been a dream of mine to represent the USA at the Olympics, and I hope there will be many more chances for me to make this 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."
The rest of the U.S. team is made up of 2021 Australian Open runner-up and world No. 15 Jennifer Brady, No. 27 Jessica Pegula and No. 35 Alison Riske for women's singles, while Nicole Melichar and Bethanie Mattek-Sands are doubles-only selections.
Fellow Americans No. 4 Sofia Kenin and No. 16 Serena Williams opted out of the games while Venus Williams, the most decorated Olympic tennis player in history with five medals, didn't qualify for the singles tournament.
Gauff last competed at Wimbledon earlier this month where she lost in the fourth round to Angelique Kerber. Gauff was expected to become the youngest Olympic tennis player since 2000, according to NBC Sports.
More Olympics Coverage: