Roger Federer is struggling and it is an unsettling sight, like Placido Domingo slurring his words. But perhaps on these ancient lawns, where his game finds its most complete expression, he will find the sanctuary he needs.

Federer has been No 1 for 229 successive weeks and till the year began had been in 10 successive Grand Slam finals.

Yet in 2008 he has won only two events of minor import, been dismissed by Djokovic off court and dismembered by Nadal on it (in Paris).

And already critics are leaping off his bandwagon, for even Bjorn Borg has said: 'I pick Rafael Nadal as (Wimbledon) winner and my second choice is Novak Djokovic, my third is Roger.'

Undeniably, Federer's superhero costume has a tear in it and some of his greatness has drained away. Illness has weakened him, the machinery of his forehand has rusted, he makes more errors than Sharapova issues grunts, and his confidence is shaken.

In 2006, the gap between him and the No 2 at this time was 2,715 points, in 2007 it was 2,065, and now Nadal is only 1,145 points away. His career is scarcely over but his reign is under threat.

Said Djokovic this week: 'Some things are changing. I think (Federer's) a little bit shaken with that loss (in the French final) and mentally he has been struggling in the last couple of months.

'New names are coming, fresh talented players who believe more they can win against him and I am one of them. Suddenly he is worried a little bit.'

But sometimes an athlete returns to familiar ground and finds his powers restored, a bit like Clark Kent walking into a telephone booth.

Certainly for the Swiss, Wimbledon is his spiritual home, and Centre Court, to borrow a phrase from Boris Becker, is his living room. Or, as the Swiss laughed last year: 'I've got the keys to it at the moment, for sure.'

In a tournament with a royal box, his stylishly haughty game fits; in an event where the men's draw is known quaintly as the 'Gentlemen's singles', his old-fashioned manners sit comfortably.

Few advertising hoardings litter Wimbledon and its reigning champion is not given to glitz either. This pristine player looks best in Wimbledon white.

At this oldest of Grand Slams, winning is like a badge of authenticity. Here Borg was baptised a great, Becker announced himself, Sampras served up history and Navratilova became a legend.

Here, Federer's fast court game stings and his record is fearsome. If Nadal has lost only seven sets in winning four successive French Opens, Federer has given up only eight sets in taking home five straight Wimbledons.

As he says: 'I haven't lost on grass for six years. I still definitely feel very strong about my chances and being the big favourite going into grass.'

But it does not help Federer that Nadal and Djokovic, both of whom he must beat to regain his title, have unveiled superior models of themselves this year.

But this is expected, for the Swiss, almost 27, is a finished product, while the Spaniard, just 22, and Serb, just 21, are unfinished constructions.

Said Nadal after winning Queen's last week: 'I think I improve my tennis, so I have more options to do when I am playing. So I can slice some more balls. I can go to the net more times. The forehand I am playing good, too.'

Only these three men can win Wimbledon and history is on their mind.

Federer is in pursuit of William Renshaw's record of six consecutive Wimbledon titles won between 1881-86; Nadal is attempting to be the first man since Borg in 1980 to win the French Open and Wimbledon in the same year.

The Spaniard's form is glittering, his ability to switch from the clay-slide to the grass quick-step is remarkable, and his competitiveness would make a Cape buffalo blush. But his finest advantage is not muscle, or speed, but what grows beneath him.

Wimbledon's courts are reportedly harder than before (especially when the sun is out), the grass slower, the balls heavier.

Twenty years ago, slices stayed low and balls slithered and skidded; now balls bounce higher and not as fast.

Once nimble serve-volleyers named McEnroe, Ivanisevic, Becker, Edberg, Rafter, Sampras - many of whom would have eaten Nadal for lunch on quick grass - danced to the net every point and defied rivals to pass.

Now, men like Nadal are neither challenged by quality serve-volleyers for this art form has died, nor make more than the occasional foray to the net themselves.

Simply, sadly, grass-court tennis has become mostly baseline tennis, and it has emboldened Nadal and Djokovic, for as the Serb admits: 'The grass is slower and the baseline players have so much more success, which is why I am hoping I can do well.'

Federer, nevertheless, must charge the net like a one-man cavalry. He must know most champions misplace form and then refind it. He must remember Nadal still lacks his versatility.

And he must memorise the words Sampras recently said of him: 'I think when push comes to shove in the majors, (Federer's) still the guy that's most likely to win them.

'He's lost a couple and, if anything, that'll do him some good, it'll get him going and fired up.'

If eras have defining moments, this fortnight could be Federer's. We can quibble about this being minor slump or major slide, but clearly he needs to make a statement, send a reminder to the field about his greatness.

And if the Swiss has forgotten how, he can call an old friend in hospital for advice. Mr Woods has a lot of free time to help.

rohitb@sph.com.sg