RAFAEL NADAL could become the No.1 tennis player in the world at the Olympics.

Roger Federer has held top spot for 232 consecutive weeks. Nadal has been in his wake for 155 of them. But after becoming the first player since Bjorn Borg in 1980 to complete the French Open-Wimbledon double, Nadal is on the verge of the unthinkable. Debate used to centre on whether Federer was the finest athlete on the planet. Now it's about whether he's the best tennis player.

Federer snapped at reporters at the All England Club when it was suggested Nadal was motoring towards the top ranking.

"You write what you want," he told reporters following his 12th defeat to Nadal in 18 matches in their five-set Wimbledon thriller. "I'm going to try and win the Olympics and the US Open and then we can talk again."

Federer has a poor Games record.

He lost the bronze-medal match at the 2000 Olympics in Sydney and was knocked out in round two at Athens by Thomas Berdych of the Czech Republic.

"At the end of your career, you're going to be judged on the grand slams you win and number ones," Federer said. "The Olympics are a new thing to tennis."

Nadal is up for it. Nadal is up for anything.

"To play in the Olympics is very special - when you're very young you always see the Olympic Games on television," said Nadal, who is making his singles debut in Beijing having played doubles with Carlos Moya at Athens four years ago.

The next two months are crucial in the rankings race and the Olympics again have points on offer. Last year in the US, Federer won and finished runner-up in the two hard-court Masters Series events in North America before the US Open, which he also claimed. He must defend all those points or the slide will continue.