Former world number one Andy Murray has explained why he withdrew from the Citi Open, claiming exhaustion was the main reason after a 3am last-16 finish, Sky Sports report.

Murray, who is still recovering from a long term hip problem that kept him out for almost a year, was playing in his first event since pulling out of Wimbledon last month.

The Scot showed plenty of promise in Washington, defeating fellow Brit Kyle Edmund in the second round before coming out on top in a marathon last-16 encounter with Marius Copil which finished in the early hours of Friday morning.

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However, with Murray scheduled to face Alex de Minaur on Friday night in the quarter-finals, the three-time Grand Slam champion decided to pull out of the competition.

In a statement on the ATP website, two-time Wimbledon winner Murray revealed his reasons for his withdrawal.

I’m exhausted after playing so much over the past four days, having not competed on the hard courts for 18 months.

I also need to be careful and to listen to my body as I come back from a long-term injury.

The Scot, who has also decided to withdraw from the Rogers Cup next week, will next be in action at the Western and Southern Open, starting on August 13 in Cincinnati.