PARIS (AFP) - Ten years after Roger Federer made his Grand Slam breakthrough at Wimbledon, the 17-time major winner returns to the All England Club next week as defending champion, but with the clock ticking.

The Swiss put his growing army of critics firmly in their place in 2012 when, after back-to-back quarter-final defeats, he captured his seventh Wimbledon title, equalling the record of Pete Sampras.

Federer, meanwhile, ended a 10-month title drought at the weekend when he won the Halle grasscourt tournament for the sixth time -- it was his first piece of silverware since Cincinnati on the eve of the 2012 US Open.

That would have spiced up his confidence ahead of Wimbledon, but there are huge doubts over whether or not he can carry that spring in his elegant step onto the famous lawns of south-west London and be the first man to win Wimbledon eight times.

Age is a factor. Federer will be 32 in August while Sampras won the last of his Wimbledon titles as a 28-year-old in 2000.

An eighth victory for Federer next month would make him the second oldest champion at Wimbledon in the Open era, just behind Arthur Ashe who was six days short of his 32nd birthday when he triumphed in 1975.

Then there will be the all-important seedings which will be announced on Wednesday where two-time champion Rafael Nadal, fresh from a record-breaking eighth French Open victory, is likely to be seeded five.

That could see Federer facing his old rival as early as the quarter-finals while Novak Djokovic and Andy Murray, the runner-up last year, are potential semi-final opponents.

It's a far cry from 2003 when Federer won his first Wimbledon, two years after beating his great hero Sampras in the fourth round and 12 months after a reality-checking first round howler against Mario Ancic.

Back then, his quarter-final opponent was Sjeng Schalken while Andy Roddick, who he went on to beat in three finals, was overcome in the semi-finals before a straight sets win over Mark Philippousis, ranked 48, in the title match.

But Federer insists his mind is free of clutter ahead of Wimbledon, buoyed by the omens of Halle -- he has completed the Halle-Wimbledon double four times already, between 2003 an 2006.

"It's totally different (than 2003)," he said. "Ten years ago I went into Wimbledon with so much pressure, even though I had lost in the first round the year before.

"In terms of needing to prove my point that I was a legitimate Grand Slam contender, I had incredible pressure. Now, ten years later, I know Wimbledon, I know Halle, I know my way around and what I need to do to perform well.

"I'm going in with pressure because I'm defending my title. There's always pressure because it's a privilege to play at Wimbledon and I want to do so well. I feel good right now and I hope I can show it on the court."

Federer has confronted doubts on many occasions in his career and faced them down with his trademark, cool self-confidence.

It's a rock-solid self-belief often interpreted as arrogance, a trait which has even spawned a parody Twitter account, @PseudoFed, which has over 20,000 followers.

On the site, he is lampooned as a man who employs lackeys to carry out routine jobs such as rolling his eyes for him.

The real Federer, who will be playing Wimbledon for a 15th time, was happy to roll his own eyes when more doubts were raised over his staying power in the aftermath of his French Open quarter-final defeat to Jo-Wilfried Tsonga.

He is used to fielding the questions and giving his answers on court.

In the Roland Garros final in 2008, Nadal allowed him just four games in his worst Grand Slam humbling.

But he recovered from what could have been a shattering loss to win the 2008 US Open, 2009 French Open, 2009 Wimbledon, the Australian Open in 2010 and Wimbledon again last year.