The sun will rise over the red clay of Roland Garros on Monday, yet that appears one of the few certainties as the French Open gets underway.

The second major tennis tournament of the season finds the world's top female player and last year's French Open champion, Justine Henin-Hardenne, slowed by a mysterious viral infection that has sidelined her from tournament play since April.

On the men's side, defending champion Juan Carlos Ferrero is hampered by wrist and rib injuries and has asked that his opening match be delayed until Tuesday.

Neither Williams sister is in peak form. Serena Williams, who defeated her older sister, Venus, to win the 2002 French Open, is still finding her footing after undergoing knee surgery. Venus withdrew from the German Open earlier this month with a twisted left ankle and has been slowed by a nagging abdominal strain.

It may just be that the most fit and fresh player entering the two-week tournament is 47-year-old Martina Navratilova, who last won at Roland Garros 20 years ago and was granted a wild-card singles entry.

Navratilova's return to singles play will surely generate the most interest, and she will open against Argentina's Gisela Dulko, 19, who has never won a match in a major tournament.

According to U.S. Olympic and Federation Cup coach Zina Garrison, who recently spoke with the veteran, Navratilova enters the tournament with no expectation of adding to her 18 Grand Slam titles. "She understands that in order for her to play her top doubles, she needs to play some singles matches and get herself physically ready," said Garrison, 40. "That's why she's actually playing."

Navratilova continues to be a force on the doubles circuit but is 0-2 since returning to singles this spring, having lost in the first round of recent tournaments in Florida and South Carolina. Still, Garrison believes opponents would be foolish to dismiss her.

"There's still not too many people out there in better shape than she is," Garrison said in a conference call last week. "She goes at everything 100 miles an hour. She still eats extremely well and works out very hard. Her body looks like a 25-year-old's -- easily."

But the sentimental story line is likely to be overshadowed by the more troubling issue of the injuries plaguing the women's tour and what, if anything, to do about the unwieldy schedule that many believe is the culprit.

"Because of the injuries we're starting to see, there's obviously a problem with playing too much," Garrison said. "The French is always very tough on your body, mentally and physically. There have just been so many injuries in women's tennis that whoever is in the best shape will win the tournament."

Second-ranked Kim Clijsters has withdrawn from the tournament with a wrist injury. Back ailments have slowed both Jennifer Capriati and Amelie Mauresmo, who is playing the best clay-court tennis on the women's tour.

French Open officials have taken the Williams sisters' injury history into account in the seedings for the tournament, bumping each up five spots higher than her current world ranking. Serena, ranked seventh, is seeded No. 2, behind Henin-Hardenne. Venus, ranked ninth, is seeded No. 4. The draw means the sisters can't meet in the final, but would meet in the semifinals if they play through.

On the men's side, top seed Roger Federer of Switzerland is currently without peer. The world's No. 1 player is chasing his second Grand Slam title of the season, having won the Australian Open earlier this year. And it looks as if he's ready to extend his dominance to clay after beating the top player on the surface, Argentina's Guillermo Coria, in the finals at Hamburg last week.

Federer's last two trips to the French Open ended with first-round losses. Coria hadn't lost on clay since last July and won the first set against Federer before falling, 4-6, 6-4, 6-2, 6-3.

Ferrero, the defending champion from Spain, is also at home on clay, but he hasn't played much lately.

Nor has Andy Roddick, last year's No. 1 player, who has played just one tuneup on European clay, making an early exit in Rome. The hard-serving American is more suited to hard courts; clay negates his biggest weapon. To compensate, he arrived in Paris last week to launch into preparations, hoping to redeem his reputation on the vexing surface.

"When I'm not playing my best tennis, it shows a little more on the dirty stuff," Roddick said in a conference call from Paris last week. "My first goal is to get past the first round this year. I'm over here early, training every day, so there's no excuse if I don't perform up to what I feel is necessary."