http://sports.espn.go.com/sports/tennis/wimbledon09/news/story?id=4274664 LONDON -- Roger Federer is sad Rafael Nadal's knee injury has put a temporary halt to one of the sport's greatest rivalries, the world No. 2 said on Saturday. Nadal, who beat Federer in an epic five-set Wimbledon final last year, withdrew on Friday with tendinitis in both knees, leaving the Swiss to once again open play on Centre Court on Monday, albeit a little sheepishly. "I shouldn't deserve it this year because Rafa deserves it [as champion] but I am obviously very honored that the championships chose me again to open the tournament," said Federer, who trails Nadal 13-7 in head-to-head meetings. Nadal's decision to pull out opens the door for Federer to win a record 15th Grand Slam, although the five-time Wimbledon champion would prefer to make history with another clash against his great adversary. "We played the last three years against each other here at Wimbledon," Federer told reporters. "So we definitely won't see the same final again. That's disappointing for me, of course, because I'd love to play him. "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." Federer said he had an inkling Nadal was struggling when they had a brief chat at Wimbledon on Wednesday. "We had a quick a 10-second chat maybe," said Federer. "He congratulated me for Paris. It was good to see him. "I asked him how his knee was. He was like, it's okay. So I kind of knew it wasn't great, because he's very honest to me. So I knew that something could be coming up." While Federer will have a chance to rewrite the record books with a 15th Grand Slam title, all he really wants is his Wimbledon crown back after it was wrestled from his grasp 12 months ago. "The focus is on the first round and the first point, trying to regain my Wimbledon crown," said Federer. "That stands over trying to beat Pete's record right now. Once I come down to the semi-finals or final, hopefully, in 10 or 12 days, then that's also going to start creeping into my mind. "But right now, I'm just trying to regain my Wimbledon crown. I don't feel any pressure having to beat Pete's record right now, but I know that things are looking good for me." Nadal's knees were still the main talking point among the players as they milled around the Aorangi Park practice courts on Saturday. Britain's Andy Murray, who is now effectively the No. 2 seed as he goes for his first grand slam title, shared Federer's disappointment over Nadal's absence. "It's obviously a shame," said Murray, who lost to Nadal in the quarterfinals last year and was seeded to meet him in the semis this year. "I think over the last couple of days it was kind of expected, it sounded like he was struggling in the matches that he played. It's always disappointing if someone like him pulls out of Wimbledon especially when he was the defending champion. "I enjoy watching him play. He's my favorite player to watch. The fans will all be disappointed. But he's got to do what's best for him." Last year's women's runner-up, Serena Williams had a different take on the big pre-tournament talking point. "I'm sad. I'm a huge Nadal fan [but] I'm sure there's a lot of guys on the men's tour who were probably celebrating and partying," she told reporters. Information from Reuters was used in this report.