Serena Williams withdrew from the French Open on Monday before her highly anticipated match with longtime rival Maria Sharapova.

“Unfortunately I have been having some issues with my [pectoral] muscle, and it has unfortunately been getting worse to the point where right now I can’t actually serve,” she said. “It’s kind of hard to play when I can’t physically serve.”

This was the first time Williams, in her 67th Grand Slam tournament dating from 1998, has withdrawn from singles during a major tournament. It trailed another first, her first major tournament as a mother, and her first Grand Slam event after missing the previous four.

Before Monday’s announcement, Williams, 36, had been thriving at the Open. With her unaccustomed world ranking of No. 451, the 23-time Grand Slam winner had beaten No. 70-ranked Kristyna Pliskova, 7-6 (7-4), 6-4, then No. 17-ranked Ashleigh Barty, 3-6, 6-3, 6-4, then No. 11-ranked Julia Goerges, 6-3, 6-4.

“It didn’t start before I got here,” she said of the pain. “The first time I felt it was Goerges in my last match.”

She said it was an injury she had never felt before, that she doesn’t “really know how to manage it yet,” and she feels “clueless as to what to do” at this point, adding she will undergo an MRI exam on Tuesday.

“I’m beyond disappointed,” she said.

“I gave up so much, from time with my daughter to time with my family. I put everything on the court, you know. All for this moment. So it’s really difficult to be in this situation, but I always, for now in my life, I just try to think positively and just think of the bigger picture and hopefully the next events and the rest of the year.”

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