Five-times former Wimbledon champion Bjorn Borg has changed his mind about who will win this year's championship, veering towards Roger Federer [Images] instead of Rafael Nadal [Images].

After the French Open when Nadal thrashed Federer in the final for the loss of only four games, Borg, the last man to win both tournaments in the same year, said he thought Nadal would win Wimbledon for the first time.

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But after watching both men play "unbelievable tennis" to reach the semi-finals he told reporters: "Roger is playing perfect tennis.

"Before the tournament I picked Nadal just to pick someone else... Nadal has improved his game a lot since last year but if Roger is playing the way he has until the semi-finals it's going to be tough to beat Roger," Borg said.

Borg was speaking before Friday's semi-finals when Federer, looking to surpass Borg's modern-era record by winning a sixth title in a row, takes on Marat Safin [Images] and Nadal meets Rainer Schuettler.

Borg said Federer was brimming with confidence and Nadal, beaten finalist the last two years, had improved immensely on grass.

After winning the claycourt French Open, the Spaniard quickly adjusted to the slick surface by capturing the Queen's Club title a week later.

"Nadal looked like he had been practising on grass for a month... for me it was impossible to get used to the grass that quickly," Borg said.

In Paris, Borg said Federer had a bad match. "But this is his home field."

If they both make the final he added: "I'm going to be there and I hope we are going to see another unbelievable final like we did last year."

Borg said Federer and Nadal, seeded one and two, were equally hungry. Nadal to win a Grand Slam other than the French and Federer because he wanted to break records, not just at Wimbledon but for Grand Slam wins.

"Nadal has lost twice in the final and he wants to win this tournament badly. Roger wants six in a row...they push each other to perform good tennis like me and John (McEnroe) did.

"I think Roger is feeling very confident. You can see it in his face, the way he is moving on the court, the way he's hitting the ball."

Borg added he would not be upset to lose his own record. "If Roger should win for the sixth time I would be very happy for him. He is not only an unbelievable champion. He's a great person."

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