Serena Williams added herself to the list of big-name withdrawals from the US Open on Wednesday, pulling out of the year's last Grand Slam tournament because of a torn hamstring.
Williams hasn't competed since injuring her right leg in the first set of her first-round match at Wimbledon in late June.
The American, who turns 40 next month, announced her decision to sit out the US Open via a social media post. She joins Roger Federer, Rafael Nadal and Dominic Thiem in sitting out the competition in Flushing Meadows, where play begins next Monday, raising questions about what the future of tennis might look like without them.
About 10 hours after Williams' announcement, her sister, Venus, posted on social media that she too would be unable to play the US Open due to injury. Venus Williams had been granted a wild card last week.
The draw for the tournament is Thursday.
This will be the first major tournament since the 1997 Australian Open without any Serena, Venus, Federer or Nadal in the singles brackets. Venus made her Grand Slam debut at the 1997 French Open; Serena arrived the next year; Federer showed up in 1999; Nadal in 2003.
Serena Williams has won 23 Grand Slam singles titles, a record in the professional era. Only one player in tennis history owns more, Margaret Court with 24.
Federer, Nadal and Novak Djokovic share the men's record of 20.
"After careful consideration and following the advice of my doctors and medical team, I have decided to withdraw from the US Open to allow my body to heal completely from a torn hamstring,'' Williams wrote in Wednesday's post.
Her note ended with: "I'll see you soon.''
Williams' coach, Patrick Mouratoglou, also put up a post on social media, saying, "We've done everything we could'' and adding: "It is heartbreaking, but this is the only possible decision.''
Williams has won six singles championships at the US Open, most recently in 2014. In her five appearances at the hard-court tournament in New York since then, she has made it to the final twice -- losing to Naomi Osaka in 2018 and Bianca Andreescu in 2019 -- and the semifinals three other times, including last year.
Her best-in-the-game serve and powerful groundstrokes have allowed Williams to remain among the title contenders at the biggest tournaments, especially on hard courts and grass.
This season, she was a semifinalist at the Australian Open in February, before losing to eventual champion Osaka there. At the French Open, Williams lost in the fourth round to Elena Rybakina.
At Wimbledon, Williams was serving while leading 3-1 in her opening match when her left shoe seemed to lose its traction while she was hitting a forehand and her right leg flexed awkwardly.
She tried to continue but eventually needed to stop playing, only the second midmatch retirement of her Grand Slam career and first since 1998.
The Associated Press contributed to this report.