Nadal withdraws from Wimbledon

He is the first reigning Wimbledon men's champion to pull out of the following year's tournament since Goran Ivanisevic in 2002. Otherwise, it hadn't happened since 1973, when Stan Smith opted not to defend his Wimbledon title because of an ATP boycott of the tournament.

Nadal has complained about his knees since a fourth-round loss to Robin Soderling at the French Open on May 31 ended his streak of four consecutive championships at Roland Garros. Later that week, Nadal pulled out of the Wimbledon tuneup tournament at Queen's Club, then went to Barcelona to have tests on his knees.

"I think I reached the limit right now. I need to reset to come back stronger," Nadal said.

Asked what sort of threat the knee problems might present to his career moving forward, he said: "It's not chronic. I can recover, for sure."

His exit opens the door for Federer to reclaim the No. 1 ranking, a spot he held for a record 237 consecutive weeks until Nadal pushed him down to No. 2 in August. Federer, who is 7-13 against Nadal, also avoided facing him at the French Open. Instead of a fourth consecutive final in Paris against Nadal, Federer faced Soderling for the championship on June 7 and won in straight sets to complete a career Grand Slam and tie Pete Sampras' record of 14 major titles.

Federer's agent, Tony Godsick, said the Swiss star would wait to comment on Nadal's withdrawal until a pre-tournament news conference on Saturday.

Nadal looked ragged during his straight-set loss against Hewitt on Thursday. But the Spaniard appeared in better condition against Wawrinka. He did not play either of the exhibitions with tape below his knees, something he usually does.

Aside from the physical issues, Nadal spoke on Friday about the mental toll the injury has taken.

"One of the big problems is, when I am playing, I'm thinking more about the knees than about the game. So that's very difficult to play well like this, no?" the six-time major champion said.

After shaking up the tournament, Nadal sat on a couch in a players' lounge area, chatting for quite awhile with his spokesman, Benito Perez-Barbadillo, and Novak Djokovic. As it approached 10 p.m. - later, even, than the finishing time of his epic match against Federer a year ago - Nadal finally rose to leave. That trio, along with his uncle and coach, Toni, walked toward one of the black steel gates that guard the All England Club's exits. The gate was locked shut.

"How do you get out of Wimbledon?" Perez-Barbadillo asked aloud.

They eventually found another - unlocked - gate, and Rafael Nadal, 2008 Wimbledon champion, departed the grounds, his 2009 Wimbledon over before he hit a single shot.

AP