Defending champion Roger Federer has been handed a bye to the quarter-finals of Wimbledon after fourth-round opponent Tommy Haas was forced to pull out through injury.

Haas, the injury-plagued 13th seed, suffered a torn abdominal muscle in his four-set victory over Russian Dmitry Tursunov in the third round.

Federer will play the winner of the match between Spain's Juan Carlos Ferrero and Janko Tipsarevic in the last eight as he bids for a fifth-straight Wimbledon title, equalling the modern-day record of Bjorn Borg.

"I felt it in my previous match," Haas revealed.

"I took painkillers in the middle of the match and they helped, as did the adrenalin you get from playing a match, but the ultrasound showed that there was a bad tear.

"I wish I could have been on Centre Court but it's not to be. Not being able to play against Roger on Centre Court is very disappointing.

"It's moments like this that you play the game for. It's why you work hard and train hard.

"The way I was playing I think I'm one of the guys who could have been dangerous for Roger. It would have been a nice opportunity."

Ironically, this was Haas' first tournament since retiring in the opening round of the Masters Series event in Rome in May with a shoulder injury.

The 29-year-old has been plagued by injury problems throughout his career, missing Wimbledon in 2002 and the whole of 2003 after two surgeries on his right shoulder, and in 2005 he injured ankle ligaments here by stepping on a ball in the warm-up before his first-round match against Tipsarevic.

"I didn't even think I would play here because of the shoulder injury but I made it and they even made me the 13th seed, which is my lucky number," Haas added.

"Then I get to the fourth round and this happens, just when I was about to play Roger on Centre Court in one of the biggest matches of my career."

At least the German had not lost his sense of humour. Asked if there was any upside at all, he joked: "I won't have to pay for my house here for another week."

Today's fourth-round action, weather permitting, will now feature American third seed Andy Roddick, the two-time finalist taking on France's Paul-Henri Mathieu for a place in the quarter-finals, while Richard Gasquet and wild card Jo-Wilfried Tsonga stage an all-French clash on court one, while Ferrero and Janko Tipsarevic play off for the right to face Federer.

Third-round matches delayed from Saturday are also scheduled to be played, with second seed Rafael Nadal up against Sweden's Robin Soderling.

The pair had actually completed their warm-up on Saturday before the heavens opened for a second, and ultimately decisive time.

Former champion Lleyton Hewitt takes on Argentina's Guillermo Canas, the man who beat Federer in successive tournaments earlier this season, while Wayne Arthurs and Jonas Bjorkman strike a blow for the older generation when they clash on court three.

Arthurs is 36 and retiring after the tournament, while 35-year-old Bjorkman is looking to repeat his shock progress to the semi-finals last year, where he lost to eventual champion Federer.