Rain could ruin the opening day's play at the French Open at Roland Garros.
Play has already been suspended on the Suzanne Lenglen court where Serena Williams is taking on Bulgaria's Tsvetana Pironkova.
Pironkova led Williams 6-5 in the first set when the players were taken off.
Number one women's seed Justine Henin-Hardenne takes on Elena Vesnina of Russia later today.
In the men's draw, Marat Safin has already booked his place in the second round by beating Spain's Fernando Vicente in straight sets 6-1, 6-3, 6-1.
Two of the top men's seeds have tough openers this afternoon.
Seventh seed Ivan Ljubcic faces home favourite Arnaud Clement, while fifth seed Fernando Gonzalez is up against the Czech Radek Stepanek.