British number one Jack Draper has withdrawn from the US Open because of an arm injury.
The fifth seed was seen as one of the contenders for the title at Flushing Meadows, having reached the semi-finals last year, but his preparations were disrupted by the injury.
The 23-year-old came through his first-round match against Argentine qualifier Federico Agustin Gomez in four tricky sets on Tuesday.
He was due to play Belgium's Zizou Bergs on Thursday.
"I tried my very best to be here and give myself every chance to play, but the discomfort in my arm has become too much," Draper wrote in a statement on X.
"I have to do what is right and look after myself."
'Bone injuries are difficult to handle'
Draper said before the tournament that he was "ready to go" despite struggling with a bruised humerus - the bone that runs from the shoulder to elbow - on his left serving arm.
He began to feel the issue during the clay-court swing in April and said it got "progressively worse" over the grass-court season.
Draper arrived in New York having not played since his second-round defeat at Wimbledon in early July, withdrawing from key tournaments in Canada and Cincinnati in order to recover.
The Englishman competed in the US Open mixed doubles tournament alongside Jessica Pegula last week and wore a sleeve on his injured arm during his first-round match.
Draper practised in New York on Wednesday morning but later announced he would be unable to continue in the tournament.
Former world number nine Andrea Petkovic said on Radio 5 Live that she was "not surprised" to hear about Draper's withdrawal.
"Adrenaline can do things to your body - you might feel fine for weeks and after a four-set match it can feel aggravated," she said.
"Bone injuries are difficult to handle. They can always come back if you come back too early."
BBC