The world number one has been knocked out in the first round in the last two years at Roland Garros but he has revealed a more bizarre statistic.

"It must be noted that I have never won a match on centre court, not even a set," Federer said.

The Wimbledon and Australian Open champion even lost an exhibition match against in-form Italian Filippo Volandri on Sunday on the Philippe Chatrier court.

The Swiss was beaten by claycourt specialists Hicham Arazi of Morocco in 2002 and Peru's Luis Horna last year but said his 2003 Wimbledon triumph had changed his approach to Grand Slam tournaments.

"I used to put too much pressure on myself but my Wimbledon victory changed that.

"Now I know how to tackle a Grand Slam. The only difference here is that the courts are slow and the balls heavy," he said.

Federer has not previously faced Vliegen but said he had seen the lucky loser play before, when he was in Dubai and the Belgian was playing a qualification match.

NAVRATILOVA RETURNS

Federer tops the bill in a hectic Tuesday at Roland Garros with most of the favourites in the top half of the men's draw in action.

Should he win his match, Federer will want to watch three-times champion Gustavo Kuerten against Spanish qualifier Nicolas Almagro as he could meet the Brazilian in the third round.

He will also keep an eye on reigning champion Juan Carlos Ferrero, who only decided to defend his title at the last minute after having his training hampered by a rib injury.

Ferrero meets German Tommy Haas, a former world number two who missed all of last season with a shoulder injury.

Australian Lleyton Hewitt will also be in action against French wildcard Arnaud Di Pasquale while Argentine David Nalbandian, seeded eighth, meets French hopeful Richard Gasquet.

In the women's draw, Serena and Venus Williams will star against Czech Iveta Benesova and Thai Tamarine Tanasugarn respectively.

But the show could be stolen by Martina Navratilova, who makes her Grand Slam singles return in a tournament she last won 20 years ago.