Elena Rybakina faces a race against time to be fit for the US Open after being forced to retire from her match against Iga Swiatek in Cincinnati on Thursday.

The Kazakh world No.2 was trailing 1-4 in the first set of their quarter-final clash at the WTA 1000 event. Serving at 40-15, Rybakina approached the net to try and pick up a return shot from Swiatek before immediately crouching over in pain. During the following point, she pulled up at the baseline and called for a medical timeout before eventually retiring. During the match, Rybakina already had tape on her left ankle and up her Achilles. However, the official reason for her retirement was an ankle issue, not her Achilles.

It is a double blow for Rybakina, who has just over a week to be fit in time for the final Grand Slam of 2026. In Cincinnati, she was in with a shot of claiming the world No.1 ranking for the first time in her career after Aryna Sabalenka was knocked out in the third round. To do so, she had to reach the final.

“Honestly, I felt a bit scared because I don’t know if I see a player having an injury like that,” Swiatek said of Rybakina’s retirement. “I wasn’t sure because she didn’t look good obviously. But then she wanted treatment, so I wasn’t sure if she’s going to be back or not. So I wanted to be really focused on just being ready because breaks like that can really throw you off of your rhythm and the momentum. But then I felt really sorry for her, but hopefully it’s nothing serious.

“I hope Elena will be fine. The next tournament is the priority. I know this one is important as well. But US Open is US Open. I hope she’s gonna be ready for that. She’s super close to being No. 1 in the world. It’s a shame,” she added.

Speaking to reporters, Rybakina confirmed she will be undergoing an MRI on Friday and said the issue she is dealing with has been bothering her for a while.

“It’s been bothering me for a long period of time. It was under control, but then after playing a lot of matches in Canada and coming here playing two matches in a row. The match against (Magdalena) Frech stopping with the rain delays, I started to feel it more, and I took a day off completely after. It was feeling okay before the match but unfortunately one wrong movement, one landing, and something happened,” she said.

As Rybakina faces an anxious couple of days trying to recover, Swiatek is relishing her resurgence on the Tour. She hasn’t lost a match since Wimbledon and recently claimed her first title of the year at the Canadian Open. As the defending champion in Cincinnati, Swiatek is two wins away from becoming the first woman in over a decade to win the event in consecutive years. The last to do so was Serena Williams, who won the title in 2014 and 2015.

Swiatek will play Jessica Pegula in the semi-finals.