London, Jul 27 (IANS): World No.1 tennis player Roger Federer says winning the Olympic gold could be harder than winning a Grand Slam title.

Federer, who made history three weeks ago by winning his seventh Wimbledon title, said Thursday that the win has boosted his confidence, but the Olympic has fewer rounds and could produce more upsets, Xinhua reports.

"I hope I can be the favourite...and be able to get going and get full fight on the court," Federer said at a press conference ahead of the London Olympics' opening here Friday.

Federer and Swiss teammate Stanislas Wawrinka won the doubles gold medal at the 2008 Beijing Games but Federer failed to get a medal in the singles event won by Spain's Rafael Nadal.

Speaking on the withdrawal of Nadal from the Games, Federer said he felt sad but expected the Spaniard to return to the court soon.

"It was a big surprise to see Rafa pull out of the Olympics as the defending champion from four years ago," Federer said. "I wish him a speedy recovery and hopefully we will see him on the tour again soon."

Federer does not rule out competing at the 2016 Rio Olympics.

"There is absolutely no plan to retire after this (London Games), and I have plans in place for next year and beyond that," the Swiss said. "Even if I do win, I will keep on playing."