Vondrousova withdraws, puts Sabalenka in semis

NEW YORK -- Defending champion Aryna Sabalenka returned to the US Open semifinals without hitting a ball on Tuesday night because the woman she was supposed to face in the quarterfinals, 2023 Wimbledon champion Marketa Vondrousova, pulled out of their match with an injury.

The U.S. Tennis Association's announcement of the walkover -- about two hours before the match was scheduled to begin in Arthur Ashe Stadium -- did not specify what was wrong with Vondrousova, though she was seen walking with a wrap around her left knee.

Vondrousova, a 26-year-old left-hander from the Czech Republic, had advanced to the quarterfinals with a three-set victory over 2022 Wimbledon champion Elena Rybakina on Sunday night. She entered the US Open ranked 60th and unseeded.

Sabalenka now will meet No. 4 Jessica Pegula in the semifinals on Thursday. That is a rematch of last year's championship match at Flushing Meadows, which Sabalenka won in straight sets.

Vondrousova has been as high as No. 6 in the WTA rankings but a series of injuries over the years kept off the tour for stretches at a time. That included operations on her wrist in 2022 and on her shoulder last year.

"So sorry for Marketa after all she's been through. She has been playing amazing tennis and I know how badly this must hurt for her," Sabalenka posted to her Instagram story. "Take care of yourself and I hope you can recover quickly."

This is the first time Sabalenka has ever advanced in a major via walkover or retirement.

The last two women's quarterfinals are scheduled for Wednesday: No. 2 Iga Swiatek vs. No. 8 Amanda Anisimova -- that's a rematch of last month's Wimbledon final, which Swiatek won 6-0, 6-0 -- and No. 11 Karolina Muchova vs. No. 23 Naomi Osaka.

That will be Osaka's first Grand Slam quarterfinal since the 2021 Australian Open, where she wound up claiming her fourth major trophy.

ESPN Research and The Associated Press contributed to this report.