From correspondents in London, England, 05:32 PM IST

Three-time winner Boris Becker can't see past Roger Federer as favourite to retain his Wimbledon tennis title with a sixth straight success.

But the German says that Rafael Nadal is fast improving as a grass-court force.

'It is very tough to go against a five-time champion,' the German told London's Daily Telegraph on Monday.

'Rafael Nadal has clearly improved greatly on grass, while Novak Djokovic is the third player in the group, but I feel that with the history Roger has at Wimbledon, the winning record, you don't bet against him in the same way that you don't bet against Nadal on clay.'

Becker, a commentator for the BBC during the fortnight, adds that Federer's third straight Roland Garros final loss to Nadal will not have affected his legendary Wimbledon confidence.

'The manner of his defeat (he won just four games) was shocking, but I don't believe it can have affected him psychologically. He always arrives at that tournament knowing that, on clay, Nadal is a little bit better, so I don't imagine mentally he is really hurt by it.

'I think he's more motivated this year because he knows that if he doesn't win Wimbledon, his number one ranking is at stake. To be recognised as the top player at the end of the year, Federer needs to win Wimbledon. That will be very much in his mind.'

(Staff Writer, © IANS)