Andy Murray has withdrawn from his Citi Open quarter-final after a late-night finish on Friday morning.
Murray had been due to play Alex de Minaur on Friday night but the three-time Grand Slam champion revealed fatigue had proved too much.
“I’m exhausted after playing so much over the past four days, having not competed on the hard courts for 18 months,” Murray said in a statement on the ATP website.
“I also need to be careful and to listen to my body as I come back from a long-term injury.
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“I’m gutted not to be playing and I’d like to thank the tournament and all the fans. There are lots of positives to take from this week, so I’ll take some time to rest and recover and then head to Cincinnati early to prepare and get ready.”
Tournament Director Keely O’Brien added: “I am so grateful that Andy, an incredible champion, came back to D.C. to begin what we all know will be a great comeback.
“I sincerely respect his decision and know that his health and recovery process is his top priority, as it should be.”
The Scot had earlier announced that he has decided to sit out next week’s Rogers Cup in Toronto and his next tournament will now be the Western and Southern Open, starting on August 13 in Cincinnati.
2:13 Murray in tears after win
Murray has been playing his first event this week since withdrawing from Wimbledon and has endured a gruelling schedule – winning a trio of three-set matches, including a marathon encounter with Marius Copil which finished just after 3am on Friday morning.
An emotional Murray was in tears after the victory and said afterwards he thought it was “unreasonable” to ask a player to finish a match so late and then be expected to play again the following day.
He also told reporters that he could “potentially” withdraw from the tournament rather than take on De Minaur.
7:10 Copil v Murray: Highlights
Murray is working his way back into form after having surgery on his right hip and spending 11 months on the sidelines.
And in the wake of his exertions this week he has also decided to withdraw from the Rogers Cup next week.
Murray said: “Sadly, I won’t be able to take my place in the draw in Toronto. I’d like to thank the tournament for a wild card, I always love playing in Canada and look forward to returning next year.
“I’ve played quite a few matches this week in Washington and I need to be smart with my rest and recovery, as I come back from injury.
“My plan is to head to Cincinnati early next week. Appreciate all the support this week in Washington, it’s amazing to be back playing.”