Novak Djokovic revealed that the elbow injury that forced him out of Wimbledon has been "bothering" him for a year and a half, and he will consider taking a break.
Djokovic needed treatment on his elbow at the end of the first set against Tomas Berdych and was already dealing with a long-term right shoulder problem.
The three-time Wimbledon champion, who would have regained the world No 1 ranking if he had won the tournament, was trailing 7-6 (2) 2-0 when he called it quits on Court One.
Czech world No 15 Berdych, the 2010 Wimbledon runner-up, goes on to face seven-time champion Roger Federer for a place in Sunday's final.
"It's my elbow. It's been bothering me for a year and a half. It's unfortunate I have to finish Wimbledon like this," said Djokovic after his first Grand Slam retirement since the 2009 Australian Open quarter-finals.
"I started feeling it at the beginning of the tournament. The level of pain was always increasing and today was the worst day. I tried what I could do to get it in condition to be able to play.
"All the treatments couldn't really help. The serve and forehand were the shots I could feel it most."
Djokovic was especially frustrated to have had to pull out with an injury after complaining bitterly that Wimbledon organisers should have allowed his last-16 match to be played on Monday evening instead of Tuesday morning.
The 12-time Grand Slam champion had to face Adrian Mannarino a day later than scheduled due to the late finish of Rafael Nadal's defeat against Gilles Muller.
Djokovic had needed treatment on his shoulder during his victory over Mannarino.
"Those kinds of circumstances don't really help. This is the kind of situation you have to accept and try to make the most out of it," Djokovic said.
"I spent about two hours on the treatment table in between the warm-up and the match to make me fit. It wasn't to be. For an athlete in an individual sport, there is no way out when you are injured.
"I will have to take some time and see what needs to be done. I guess a break is something I will have to consider right now.
"I never had a rest throughout my career. I had a schedule to play all the time. The specialists that I've talked with, they haven't been really too clear, mentioning also surgery, mentioning different options. Nobody was very clear in what needs to be done.
"As long as it kind of comes and goes, it's fine, but obviously, adding up, maybe it worked for seven, eight, 10 months, but now the next seven months is not working that great.
"Obviously it's adding up more and more. The more I play, the worse it gets."
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