Roger Federer has said that he is sad that Rafael Nadal's knee tendonitis has postponed one of sport's greatest rivalries.

Rafael Nadal, who beat Federer in an epic five-set Wimbledon final last year, withdrew on Friday with tendinitis in both knees, leaving Roger Federer to once again open play on Centre Court on Monday.

"I shouldn't deserve it this year because Rafael Nadal deserves it but I am obviously very honoured that the championships chose me again to open the tournament," Federer, who trails Nadal 13-7 in their head-to-heads said.

Federer could win a record 15th grand slam at Wimbledon although Federer, the five-times Wimbledon champion, said that he would prefer to make history with another clash against Rafa Nadal.

"He's my main rival. We've had some wonderful matches over the years, and especially the one here last year was the one that obviously stands out. That we can't potentially repeat that is obviously sad. I'm also sad for him because it must have been a very difficult decision to make."

Rafael Nadal's withdrawal from Wimbledon drastically altered Wimbledon odds, the favourite remains Roger Federer however the Swiss has dropped to 10/11 with SkyBet. Rafael Nadal's withdrawal also affected Andy Murray's Wimbledon odds with Murray standing at 7/4 with Bet365.