John Isner, of the US, serves to Spain's Tommy Robredo during their third round match of the French Open tennis tournament at the Roland Garros stadium, in Paris, France, Friday, May 30, 2014. (AP Photo/David Vincent)
Switzerland's Roger Federer returns the ball to Russia's Dmitry Tursunov during the third round match of the French Open tennis tournament at the Roland Garros stadium, in Paris, France, Friday, May 30, 2014. (AP Photo/Darko Vojinovic)
Spain's Rafael Nadal returns during the third round match of the French Open tennis tournament against Argentina's Leonardo Mayer at the Roland Garros stadium, in Paris, France, Saturday, May 31, 2014. (AP Photo/Michel Euler)
France's Gael Monfils, right, and Italy's Fabio Fognini shake hands after their third round match of the French Open tennis tournament at the Roland Garros stadium, in Paris, France, Saturday, May 31, 2014. (AP Photo/David Vincent)