Champion Rafa Nadal and the three other leading men's contenders charge into Wimbledon with major expectations despite all battling minor fitness issues in the run-up to the grasscourt Grand Slam.

World number one Nadal has not lost a match at the All England Club since the 2007 final, ripping away six-times champion Roger Federer's aura of invincibility on the south-west London lawns in the process.

But next week will be the first time the Spaniard will actually walk out as defending champion having missed the 2009 event through injury.

His tired display when losing to Jo-Wilfried Tsonga at Queen's last week showed his sixth French Open title had taken its toll on his fitness and he will hope to have recharged his batteries after heading back to Mallorca for golf and fishing.

Third seed Federer, beaten yet again by Nadal in the Roland Garros final this month, skipped the Halle grasscourt tournament with a groin problem and Serbian world number two Novak Djokovic missed Queen's with tendinitis in his knee.

Fourth seed Andy Murray triumphed at Queen's on Monday after battling an ankle problem picked up in Paris but despite a few weary limbs, it is difficult to look past the quartet.

"You've got to start with the top four," Brad Gilbert, a former top 10 player and once coach to Andre Agassi and Murray, said when asked who would be holding aloft the trophy on July 2.

"They kind of separated themselves. I mean, Rafa's played tremendous, Fed's got a track record, Djokovic has been on fire this year, and Murray just won Queen's.

"Some guys could make some runs, but winning this tournament will be one of those four guys for sure."

Nadal and Federer have won the men's singles title at Wimbledon every year since 2003 and have played each other in three finals, one of them a spine-chilling epic in 2008 which Nadal edged in near darkness.

For the first time since their duel domination began, however, Swiss Federer is not one of the top two seeds.

Nadal heads to London not just defending his title but clinging to the world number one spot by his fingertips, with Djokovic hot on his tail after a run of 41 straight wins in 2011 which was ended by Federer in a French Open semi-final classic.

Federer, whose elegant tennis down the years at Wimbledon has been in such stark contrast to the muscle-bulging power of Nadal, will aim to prove that at 29 there are still a few golden chapters left in his career.

Then there is Murray, Britain's best player in living memory who has continually fluffed his lines with the big prizes tantalisingly close despite his sublime skills.

Sweden's Robin Soderling and three-times runner-up Andy Roddick may shine and fans thronging the grounds can expect entertaining cameos from the likes of acrobatic Frenchman Tsonga and iron-wristed Tomas Berdych, last year's beaten finalist.

But as they proved at Roland Garros by making the last four, Nadal, Djokovic, Federer and Murray are a class above the rest.

Nadal displayed the depth of his mental fortitude in Paris.

Out of sorts to start with, he almost lost to John Isner in the first round and looked anxious before his game caught fire.

The 25-year-old then took his Grand Slam singles title tally to 10 compared to Federer's record of 16.

"I am very confident. I'm going to be there with high motivation and hopefully in perfect performance physically," Nadal said of Wimbledon.

Federer, overpowered by Berdych in the quarter-finals a year ago, said recently he was playing "pressure-free" for the first time in his illustrious career and now has his eye on a seventh title to match the modern-era record of American Pete Sampras.

"Wimbledon for me is always the number one goal in the season," Federer said after pushing claycourt king Nadal hard in the French Open final. "This is where it all started for me back in 2003. That's why I always really enjoy coming back."

Of the top four, only Murray is without a Grand Slam title.

The Briton, trounced by an inspired Djokovic in the Australian Open final in January, was magnificent in winning the Queen's title but knows ending his country's 75-year wait for a men's Grand Slam champion will be much tougher.