On Wednesday, Serena Williams has been pulled out of the French Open after aggravating her left Achilles’ tendon injury shortly before she was scheduled to play a second-round match.

She has hinted that the injury might keep her from playing another competitive match this year.

The 39-year-old tennis player said she needed at least “four to six weeks of sitting and doing nothing,” citing the injury.

Williams, who won 23 Grand Slam singles titles, said her left Achilles’ tendon, which required treatment during her U.S. Open semifinal loss to Victoria Azarenka, had not sufficiently healed.

She said she consulted with her coach, Patrick Mouratoglou, and they mutually agreed that it was unwise for her to continue to play.

In a virtual news conference, Williams said, “I really wanted to give an effort here, but just looking long-term in this tournament, will I be able to get through enough matches? For me, I don’t think I could.”

Earlier this month, the quick turnaround from the U.S. Open in New York has been an issue for a few top players.

The French Open was postponed due to high rates of COVID-19 infection in France. Naomi Osaka had to withdraw from the French Open two weeks ago citing a hamstring injury.

Within a few hours of Williams’ withdrawal, Azarenka was out as well, who was beaten by Anna Karolina Schmiedlova.

So, the withdrawal of Williams and the defeat of Azarenka mean that none of the four women’s semifinalists from the U.S. Open are left in the French Open draw.

Azarenka has pressed right back into action in Rome after losing to Osaka but the transition from hard to clay courts is not easy for many players, as it requires different tactics and footwork, including frequent sliding. For players carrying any injury, the switch could be more difficult.