Venus Williams testing her limits

What to watch on Day 3: Tournament favorites Serena Williams and Maria Sharapova begin their French Open campaigns after unexpectedly dominating the warm-up events on clay, with Sharapova the second match on Court Suzanne Lenglen and Williams fourth on Court Philippe Chatrier. Nadal's domination of the men's clay-court season, on the other hand, is all too familiar, and he is expected to make a strong start in his first-round match Tuesday afternoon and joint main rivals Novak Djokovic and Roger Federer in the second round. Nadal's potential semifinal opponents, David Ferrer and Andy Murray, are also expected to roll, but this will be the first test of Murray's back since he lost early in Rome.

Americans Sam Querrey and Donald Young will look to build on their compatriots' strong showing so far at this year's French Open, with Querrey hoping to challenge eighth seed Janko Tipsarevic and the underperforming former phenom Young facing the underperforming current phenom Grigor Dimitrov.

PARIS -- Venus Williams doesn't know how she'll feel when she steps out onto the court to face Agnieszka Radwanska in the second round of the French Open. But she knows she won't react the same way she did when she last played Radwanska.

That meeting was in the quarterfinals of the Sony Open in Miami, Williams' first tournament back since being diagnosed with the autoimmune disease Sjogren's syndrome, which causes joint pain and fatigue. Until then, her comeback had been off to an impressive start. She had won four matches in a row, three that went three sets, defeating Wimbledon champ Petra Kvitova and former French Open champ Ana Ivanovic along the way.

But when Williams played Radwanska, she struggled physically, and she didn't know how to handle it. "I'm in a place where I'm learning how to play with this," Williams said in an interview in Rome two weeks ago. "I think when I first started, you know, if I felt really bad, I would panic. In Miami, I panicked in the quarters. Now if I don't feel well, I just take it point by point and just do the best that I can. I'm taking it step by step."

The first step was simply understanding what was wrong. Williams shared the news of her illness during the U.S. Open last year. "I think receiving a diagnosis made a big difference for me," she said. "It makes it easier for me to understand why I feel the way I feel instead of being in the dark and just completely confused every day of the week."

The next step: accepting the situation. She struggled to come to terms with the illness for about eight months, she adds, but now knows it is something she has to learn to manage. "Yeah, I'm getting more calm, because I realize this is my life now, and I have to do the best I can with this," she said.

But knowing how to manage it is something else altogether. After coming through her opening match at the French Open in three sets, Williams admitted that much was still a mystery. "I don't know what helps, what hurts, so it's all so new I don't even know what makes a difference and if I can make a difference," she told reporters. "So I don't know if it's things I do or don't do, or if it's just the day."

She still has her down moments. "Sometimes I wonder if it's something that I'm doing. 'Did I do something wrong?'" Williams said. "But then I snap out of that pretty quick nowadays."

Williams rarely gives much away, so that kind of revelation is almost the equivalent of a weepy tell-all TV interview for her. She has been emotional during news conferences of late, appearing to be near tears when told in Rome that she was moving into the top 50. In Paris, she frequently broke into laughter, sometimes even after mundane utterances.

The seven-time Grand Slam champion is back largely to try to qualify for the Olympics, a goal she has likely achieved and could clinch by winning her second-round match. In order to get a spot, Williams would need to be at least the fourth-highest-ranked American and have a world ranking not much higher than No. 56. She is currently No. 53 (and rising) and the third-ranked American. Entries will close after the French Open.

Williams has a decorated Olympic past, winning the singles gold in 2000 and the doubles in 2000 and 2008 with sister Serena. If she gets to play another Games later this summer, "You might not see me the rest of the year," she warns.

But Williams also has a larger goal. "I have this challenge ahead of me to see how far I can get, and see, how much back I can get," she said. "So that challenge is important for me to face and to have the courage to face it."

A rematch against world No. 3 Radwanska will be a significant test of how far she has come. Williams' game is clearly still effective at the highest level, but her serve and forehand have also shown their old tendency to break down at times. And though neither of the two is particularly fond of clay, Radwanska's game is far more suited to the surface. On the other hand, she has also been dealing with a back problem and could be tired after playing and winning the title in Brussels last week.

Whatever the outcome, however, Williams will learn a little more about where she's at, and where she's going, in this new journey of hers.

Novak Djokovic may be Rafael Nadal's biggest rival for this French Open but Nadal biggest rival in the history books is Bjorn Borg, the man whose record of six French Open titles he will be trying to break over the next two weeks. If he does, Nadal will also tie Borg with 11 Grand Slam wins, taking him to joint fourth on the all-time list and one closer to Federer's 16.

So while much of the talk has centered around Novak Djokovic's pursuit of the "Novak Slam," Rafael Nadal is also chasing some big achievements at this event.

The Nadal versus Bjorn Borg debate has raged for a few years now. Who's the greatest of all time on clay? Although many feel Nadal has already surpassed Borg, many others feel that it will take a seventh French Open for Nadal to eclipse the legendary Swede.

But Nadal has been making a strong case as far as numbers are concerned.

Some of Borg's titles and matches may be undercounted because of the greater ambiguity between official and exhibition events at that time, so the race could be closer than it looks. But though Borg retired near the peak of his career, Nadal looks set to carry on for a while, providing his body holds up.

The Spaniard can sometimes sound disenchanted about the grind of the tour: "Seems like I am playing for 100 years here on the tour," he said last year. But his desire and motivation appear to be undiminished. As usual, his approach to the sport is unchanging -- win or lose, record or no record.

"I am coming here with [the same] motivation of every year," he told reporters ahead of the tournament. "I [am] not going to be more motivated because I have six and can win seven. And I was not more motivated when I arrived here in 2005 than today. I was not more motivated in 2010 [than] when I lose in 2009. The motivation is always the same. Sometimes you lose, sometimes you win. That's the sport."

This attitude may help Nadal remain more resilient to defeat than Borg, whose losses to McEnroe at Wimbledon and the U.S. Open hastened his decision to retire. Nadal, who took seven losses in a row to Djokovic between this season and last, has hung tough and won their past two encounters, both on his favorite red clay.

One side effect of Borg's early departure was that his record remained untarnished by defeats later in his career, while Nadal's aura of invincibility was somewhat dented by the losses to Djokovic last year. But if the Spaniard can reclaim the edge, his legend will grow even greater than before.

But that is some way off. First the groundwork must be laid in the early rounds, starting with Simone Bolleli in his opening match on Tuesday.