Andy Murray says it is “completely normal” to have doubts about whether he can return to the top of the game after his Grand Slam return ended in a second-round defeat at the US Open.

The British former world number one lost in four sets to Spanish 31st seed Fernando Verdasco at Flushing Meadows.

Murray, 31, was playing best-of-five matches for the first time since hip surgery in January.

“You just don’t know exactly what’s round the corner,” he said.

Murray, a three-time Grand Slam champion, has only played five tournaments since returning to the ATP Tour in June after an 11-month absence with the hip problem.

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Now ranked 382nd in the world, Murray said he played some of the best tennis of his comeback against Verdasco, but also lamented making mistakes and admitted it “wasn’t the most comfortable” he had felt on court.

“When I got the injury, I was ranked number one in the world, 12 months later things completely changed,” he said.

“If things keep going smoothly, physically I continue to improve, I believe that I will get back to competing for the biggest competitions because there’s no reason why I couldn’t.

“When you continue to build up and start playing more tournaments, you don’t know how you’re going to respond.

“Because of the path that I’ve been on the last year with the many ups and downs, trying to come back, it not quite working, then ending up having the surgery, I think it’s completely normal to have those doubts.”

Murray eyes Davis Cup return

Murray says he would “love” to play in Great Britain’s Davis Cup tie against Uzbekistan in Glasgow next month.

But the Scot says he needs time to assess his fitness after his US Open exit.

“Potentially it’s the last time I’d get to play competitive tennis in Scotland so I’d like to do that,” he said.

“I’d have to chat to my team because this is obviously a very important period in my rehab and my long-term strategy.”

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Murray has long carried the flag for British tennis and helped his nation win the Davis Cup for the first time in 79 years when they beat Belgium in 2015.

He has not played in the competition since Britain suffered a semi-final defeat by Argentina in September 2016, missing three matches since through a combination of fatigue and injuries.

After returning to competitive action in June, he pulled out of Wimbledon before making his Slam return at Flushing Meadows on Monday.

An opening win against Australia’s James Duckworth was followed by defeat against Verdasco on Wednesday.

“Playing five sets takes a lot out of you, which I’ve obviously learned in the last couple of days, and the Davis Cup has also taken a lot out of me,” he said.

“But there’s a big part of me that would love to play and get the opportunity to play one last time in Glasgow.”

The controversial revamp of the Davis Cup, which comes into effect in 2019, means there will only be one home or away tie each year before a season-ending final held in a neutral venue.