Serena Williams of the U.S. returns the ball during the first round match of the French Open tennis tournament against France's Alize Lim at the Roland Garros stadium, in Paris, France, Sunday, May 25, 2014. (AP Photo/Darko Vojinovic)
Switzerland's Roger Federer returns the ball during the first round match of the French Open tennis tournament against Slovakia's Lukas Lacko at the Roland Garros stadium, in Paris, France, Sunday, May 25, 2014. (AP Photo/Darko Vojinovic)
Venus Williams of the US serves the ball during the first round match of the French Open tennis tournament against Switzerland's Belinda Bencic at the Roland Garros stadium, in Paris, France, Sunday, May 25, 2014. (AP Photo/David Vincent)
Venus Williams of the US serves the ball during the first round match of the French Open tennis tournament against Switzerland's Belinda Bencic at the Roland Garros stadium, in Paris, France, Sunday, May 25, 2014. (AP Photo/David Vincent)
Venus Williams of the US serves the ball during the first round match of the French Open tennis tournament against Switzerland's Belinda Bencic at the Roland Garros stadium, in Paris, France, Sunday, May 25, 2014. (AP Photo/David Vincent)