World number eight Tomas Berdych of the Czech Republic pulled out of the US Open on Saturday suffering from appendicitis.
The 30-year-old said he was heading back to Europe for immediate treatment and would sit out the season's final Grand Slam event which starts in New York on August 29.
"I am very disappointed to announce that I will not be able to compete at the US Open this year," Berdych said in a Twitter statement.
"I was just diagnosed with appendicitis in Cincinnati so I will be flying back to Europe for additional checks and treatment.
"I will need to take some time off to recover fully but I know that I will get back as strong as ever."
Berdych, 30, was a semi-finalist at the US Open in 2012.
Berdych, this year's Wimbledon semi-finalist who is still waiting for his first Grand Slam title, recently hired former Wimbledon champion Goran Ivanisevic as his coach. The Czech parted ways with Venezuelan coach Daniel Vallverdu in May.
Berdych was eliminated by Spain's Marcel Granollers 6-3, 7-6 (7-4) at the ongoing Cincinnati Masters.
— Tomáš Berdych (@tomasberdych) August 20, 2016