Serena Williams has withdrawn from the French Open 2011 field as she continues to recover from health issues that had kept her away from competition for nearly a full year.
Williams has had two foot surgeries, and issues with blood clots in her lungs, over the past 10 months. Serena last played a professional tournament in July 2010, and has dropped to No. 17 in the world rankings.
Serena's sister, Venus, also appears unlikely to play in the French Open. She is still recovering from a hip injury that has kept her away from the court since January.
Serena isn't the only former world No. 1 to withdraw. The tournament also announced that Dinara Safina will not participate in the French Open as she continues an indefinite leave from the sport following major troubles with her game.
On the men's side, David Nalbandian was forced to pull out because of a virus.
The French Open beings play on May 21 from Roland Garros.