Serena Williams will not take part in this year’s US Open after pulling out of the Grand Slam tournament as a result of a torn harmstring.

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. The draw for the tournament is Thursday.

This will be the first major tournament since 1997 without any of Williams, Federer or Nadal in the singles brackets. Williams made her Grand Slam debut at the 1998 Australian Open; Federer made his the following year; Nadal in 2003.

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.

“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.”