The French Open begins on Sunday, but Venus and Serena Williams won't be the there because of health and injury issues. Dinara Safina won't be there, either, because of ongoing back pain, and Timea Bacsinszky will skip Paris because she is recovering from left foot surgery.
What about the players who will be there? I don't have any up-to-date news on Nadia Petrova, but she has been dealing with dizziness for several weeks. 2010 runner-up Sam Stosur had to take anti-nausea medication before she played the Rome final, and is having some medical tests run. Yanina Wickmayer had to retire in the third game of her Brussels quarterfinal today because of back pain, and Victoria Azarenka recently injured her elbow. Flavia Pennetta has recently returned from a significant shoulder rehab, but seems to be okay.
Kim Clijsters injured her wrist, shoulder and ankle, and only just decided she was healthy enough to participate in the French Open. She reports that her wrist and shoulder are fine, and she'll have her ankle taped in Paris.
Some players can play through mild-to-moderate injuries quite well; others are more fragile. In cool, damp conditions, tennis balls become heavy and more stress is put on the body, especially on red clay. World number 1 Caroline Wozniacki has embarked on a rigorous training campaign to prepare her for the French Open. Wozniacki, it should be noted, is healthy most of the time, anyway. Fitness can make a difference, especially in a major, so consistently good health is an advantage for the world number 1.
It's always troublesome to check the illness and injury list right before a major tournament begins, but illness and injury are part of the reality of professional tennis.