New York - Roger Federer wants to see injury-hit Rafael Nadal back playing this year despite fears that his great Spanish rival is likely to miss the Davis Cup semi-final and even write off the rest of 2012.
Nadal, the seven-time French Open champion, hasn't played since a shock second round exit at Wimbledon in June.
He was forced to sit out the Olympics to recover from more problems with his knees, a requirement which also forced him to miss the ongoing US Open where he was champion in 2010 and runner-up last year.
"It's obviously not great news but one that was a possibility," said world No 1 Federer when told that Nadal could be forced to delay his return to the tour until 2013.
That would also rule him out of the Davis Cup semi-final against the United States in Gijon from September 14-16 as well as a potential final date in November.
Nadal's name is already absent from the team list published on the official Davis Cup website for the semi-final.
"I'm not shocked about the news. I'm still hopeful that he'll be okay for the rest of the year," added the world No 1.
Federer and Nadal have developed a close bond despite their eight-year rivalry which has seen them battle for the world No 1 ranking as well as Grand Slam titles.
Between them they have won 24 of the last 30 majors.
Federer said that he and Nadal had never discussed the Spaniard's injury problems and that even if they did, their conversations would remain strictly confidential.
"I think it's quite personal except if one guy goes up to the other. But we're both very open and honest. When I ask him how he's feeling, he's not feeling well, he'll tell me, I'm tired, a little injured," said Federer.
"There's no real secrets out there because he knows and I know when we tell each other that stuff it doesn't leave the room.
"That's a nice relationship I have with Rafa. It's based on a lot of trust."
On Saturday, Federer cruised into the US Open last 16 and admitted he always knew he would return to the world No 1 spot despite a shattering 2011 semi-final defeat in New York.
Federer, the five-time champion bidding to be the first six-time winner in 87 years, defeated Spanish 25th seed Fernando Verdasco 6-3, 6-4, 6-4 to make the fourth round for the 12th successive year.
He next faces American 23rd seed Mardy Fish, who beat French 16th seed Gilles Simon 6-1, 5-7, 7-6 (7/5), 6-3.
Federer suffered a heart-breaking defeat in the semi-finals 12 months ago when he squandered a two-sets-to-love lead and two match points to lose to eventual champion Novak Djokovic.
But a seventh Wimbledon title, to take him to 17 Grand Slam trophies, put him back on top of the rankings for the first time since early 2010.
"Don't feel too sorry for me. I made the semi-finals last year and I was thinking about that match today," said the Swiss, who has already captured six titles in 2012 as well as taking the Olympic Games silver medal.
"I always believed I would get back to No 1 in the world and now that I am, it's amazing," Federer said. "It has been a great year."
Meanwhile, world No 4 Andy Murray also backed Nadal to return, but predicted it may take longer than expected.
"I'm sure he'll come back strong. It might just take a little bit more time. He's not really been out for really long periods of time beforehand. But he's always come back to be one of the best players in the world," said the Briton.