Japan's Kei Nishikori has tested positive for COVID-19 in Florida - just two weeks ahead of the US Open that begins in New York on August 31.
The 30-year-old former world No 4 has been staying at the IMG Academy in Bradenton, Florida, and pulled out of the upcoming Western & Southern Open, which is also being played at Flushing Meadows, before the Grand Slam.
In a statement on his official app, Nishikori said: "Hi everyone, I have some unfortunate news today. This morning while still in Florida, I got tested for Covid19 and tested positive. I will have to pull out of the Cincinnati tournament at this time.
"Me and my team will get tested again on Friday, at which point I will have another update. I am feeling well and have very little symptoms, but will obviously be in complete isolation for the safety of everyone.
"We were planning to fly to New York tomorrow, but will obviously now stay in Florida. Next update will be on Friday."
Nishikori, currently ranked 31 in the world, has not played a competitive match since undergoing elbow surgery in October last year, although the ongoing pandemic has meant he has missed less tennis than he might ordinarily have done.
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A number of players have already withdrawn from this year's US Open over fears of contracting the coronavirus.
Defending champion Rafael Nadal and women's world No 1 Ashleigh Barty are among those who refused to travel, while reigning women's champion Bianca Andreescu has also pulled out, saying the pandemic had compromised her ability to reach her highest level of form.
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