Roger Federer admitted on Thursday that he needs to win either the Olympic Games or next month's US Open to save his troubled season.

Federer, the dominant player of the last five years, has lost both his Wimbledon and Australian Open titles in 2008.

His spectacular fall from his lofty perch will be complete on Aug 18 - the day after the Olympic final - when he officially loses the world No 1 spot to Spanish rival Rafael Nadal.

Swiss tennis player Roger Federer gives a press conference ahead of the 2008 Beijing Olympic Games on August 7, 2008 in Beijing. Outgoing world number one Roger Federer faces a tricky Olympic opener against muscular Russian Dmitry Tursunov after the draw was made. [Agencies]

It will mark the end of his 236 weeks spent looking down on everyone else although the Swiss insists it is not the end of his era.

For a player who had compiled a record of 247 wins to just 15 defeats in three season from 2004-2006, with 34 titles, including eight Grand Slams, his current record this season of 44-11 with two titles and no Slams shows a marked dip in results.

"I think the respect is always there, that's not the problem," he said. "But there are players playing well at the moment, there's many guys playing very solid tennis.

"Over the last couple of weeks I haven't been at my best and I've lost matches I should never have lost but I didn't play badly by losing and that's important.

"Cincinnati (where he lost in the third round to Ivo Karlovic) is not a tournament that's going to make me cry for months and months. The Olympics and the US Open are the focus for me to play well. I played well on clay and I played well on grass.

"I just have to show that on hard courts so I hope to play well here."

Federer, though, did admit that he needs to win a big tournament this season or it will be a failure.

His only two tournament wins are in Estoril - until the final, where fourth ranked Nikolay Davydenko retired early in the second set, Federer hadn't even faced a player ranked inside the world's top 50 - and Halle where he played no-one inside the top 20.

Federer, in part, blamed the glandular fever he suffered at the start of the season for his dip in form.

"I'm trying to work really hard this year to get back from the sickness I had at the beginning which cost me bit of the season," he said.

"Maybe it could have paid off in my results. But at Wimbledon I lost only by a few points, that obviously hurt.

"(Winning here) would make the season a very good one. People expect more from me after a very good last five years. Obviously this or the US Open would save my season but I'm just concentrating on this now."