Rafael Nadal and Novak Djokovic aim to transform Roger Federer's golden era into a new dark age and destroy the Swiss superstar's dream of a record sixth successive Wimbledon crown.

Federer bristles at suggestions that his powers are on the wane after a season which has seen him lose his Australian Open title and been humiliated by Nadal in the French Open final where he managed to win just four games.

The world number one has not lost a match on grass since a first round exit at Wimbledon at the hands of Croatia's Mario Ancic in 2002 and, despite his Roland Garros trauma, he was buoyed by his 59th successive grasscourt win in clinching the Halle tournament last weekend.

"Many have been a little bewildered that I judge my performance in Paris as a success, but I see it like this and I will not give up my opinion," said the 12-time Grand Slam title winner.

"If you consider that I had a bad start in 2008 (because of glandular fever), I don't think you can call being in a Grand Slam final a failure.

"I haven't lost on grass for six years. I still definitely feel very strong about my chances."

With a fourth successive French Open title under his belt, Nadal has since collected his first grasscourt title at Queen's.

The Spaniard believes the Swiss would have been impressed by his Queen's win where he defeated Andy Roddick, a double Wimbledon runner-up, and world number three Novak Djokovic on the way.

"For sure he (Federer) will have noticed," said Nadal. "I think I'm playing well. And if I continue playing like this, I'm going to have chances for a good result. Why can't I win it?"

Nadal had never played on grass until two years ago, but has reached the last two Wimbledon finals and, twelve months ago, the 22-year-old came agonisingly close to upsetting Federer in an epic five-set title match.

He is bidding to become the first Spaniard since Manolo Santana in 1966 to win the men's title and the first man since Bjorn Borg in 1980 to win the French Open and Wimbledon back-to-back.

As at Roland Garros, only Djokovic looks capable of mounting a serious challenge to the top two.

Worryingly for Federer, the Australian Open winner has been placed in his half of the draw and they could meet in the semifinals.

Djokovic believes Federer is finally feeling the pressure from himself and Nadal.

"Quite some things have changed this year," said the colourful Serbian.

"It's becoming more interesting to see some new names, new faces winning the major titles, and believing more that they can win against the top players, which makes the game more interesting, of course.

"Roger is still the number one player of the world. He had good results this year but not as good as in the past four or five years when he was really dominant in the sport."

Federer begins his campaign on Monday against experienced Slovakian Dominik Hrbaty.

He could play Australia's Lleyton Hewitt ? the last man before Federer to win Wimbledon in 2002 &38212; if they both make it to the fourth round.

Nadal faces German qualifier Andreas Beck in the first round while Djokovic could face unpredictable Russian Marat Safin in the second round if he gets past Germany's Michael Berrer.

Roddick, the runner-up in 2004 and 2005, also cannot be discounted but he is still feeling his way from a back injury which sidelined him from Roland Garros.

The American saw his bid for a fifth Queen's title ended by Nadal in the semifinals and likes what he sees in the Spaniard.

"He's playing well, there's no doubt about that," Roddick said.

"I think grass helps his serve a lot, probably more so than a hard court. He feels comfortable on the surface. He's able to create big shots from odd angles, which you get a lot on this surface as well.

"Everyone acts surprised he's playing well on grass but he made the Wimbledon final the last two years, so I'm not really that surprised."

With Tim Henman now in retirement, desperate British fans have transferred their affections to fiery Andy Murray but the Scot, who missed Wimbledon in 2007 with a wrist injury, has seen his preparations hampered by a thumb problem.