The world number two Roger Federer of Switzerland showed earlier this month that he could beat Nadal on clay as he took out the Spaniard in the Madrid final 6-4, 6-4.
However at the French Open, the physically tougher best of five sets matches heavily favor Nadal more so than Federer.
Rafael Nadal ESP  vs. Fernando Verdasco ESP 
Andy Murray GBR  vs. Gilles Simon FRA 
Juan Martin del Potro ARG  vs. Novak Djokovic SRB 
Gael Monfils FRA  vs. Roger Federer SUI 
Rafael Nadal ESP  vs. Andy Murray GBR 
Novak Djokovic SRB  vs. Roger Federer SUI 
Rafael Nadal ESP  def. Roger Federer SUI 
In the women's draw, the Wimbledon champion and third seeded Venus Williams could meet former world number one Maria Sharapova in the quarterfinals. Williams is the better claycourt player however, and she will attack the Russian's serve, which has not yet fully recovered from shoulder surgery.
If Venus can battle past the world number one Dinara Safina of Russia in the semifinals, she could meet her sister and the second seeded Serena Williams in the final. Safina, though vastly improved, remains somewhat mentally suspect and could collapse on an important occasion.
Serena has lost her last four matches, partly due to a leg injury. If Venus is serving well and Serena is not ready to immediately attack her sister, Venus will quickly jump ahead in the match.
Dinara Safina RUS  vs. Ana Ivanovic SRB 
Venus Williams USA  vs. Maria Sharapova RUS
Jelena Jankovic SRB  vs. Elena Dementieva RUS 
Svetlana Kuznetsova RUS  vs. Serena Williams USA 
Dinara Safina RUS  vs. Venus Williams USA 
Elena Dementieva RUS  vs. Serena Williams USA 
Venus Williams USA  def. Serena Williams USA