Stan Wawrinka will not defend his US Open title, after confirming he is set to miss the rest of the 2017 season following a "medical intervention" on his injured knee.
Wawrinka, who beat Novak Djokovic in four sets to triumph at Flushing Meadows last year, announced earlier this week that he would not play in upcoming ATP World Tour events in Montreal and Cincinnati.
On Friday, the three-time Grand Slam champion - who has not played since making a first-round exit from Wimbledon last month - followed Djokovic in bringing his campaign to an end, telling his fans: "I will see you all in 2018!"
"I am sad to announce that after talking with my team and doctor I had to make a difficult decision to undergo a medical intervention on my knee," said Wawrinka in a post on his official Facebook page.
"This was the only solution to make sure I will be able to compete at the top level for many more years.
"This is obviously extremely disappointing, but I'm already looking ahead and planning my recovery. I love this sport and I will work hard to get back to my top level and play many more years.
"I also want to take this opportunity to thank my fans for sending plenty of messages of support during the last couple of days. I will see you all in 2018!"
I am sad to announce that after talking with my team and doctor I had to make a difficult decision to undergo a medical...Posted by Stan Wawrinka on Friday, 4 August 2017
The US Open's official Twitter account later confirmed Florian Mayer had earned a place in the main draw as a result of Wawrinka's withdrawal.