Tennis fans wait outside the practice courts for autographs from players during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Matt Rourke/The Associated Press
Sloane Stephens, of the United States, returns a shot against Johanna Larsson, of Sweden, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Matt Rourke/The Associated Press
Tennis fans watch play between Sloane Stephens, of the United States, and Johanna Larsson, of Sweden, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Matt Rourke/The Associated Press
Sloane Stephens of the U.S. hits a return to Johanna Larsson of Sweden during their match at the 2014 U.S. Open tennis tournament in New York, August 27, 2014.EDUARDO MUNOZ/Reuters
Johanna Larsson, of Sweden, returns a shot against Sloane Stephens, of the United States, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Matt Rourke/The Associated Press
A spectator wears a towel on his head at the 2014 U.S. Open tennis tournament in New York, August 27, 2014.EDUARDO MUNOZ/Reuters
Alize Cornet, of France, lays on the court after losing a point to Daniela Hantuchova, of Slovakia, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Frank Franklin II/The Associated Press
Peng Shuai of China waits for a serve from Agnieszka Radwanska of Poland during their match at the 2014 U.S. Open tennis tournament in New York, August 27, 2014.MIKE SEGAR/Reuters
Daniela Hantuchova, of Slovakia, returns a shot against Alize Cornet, of France, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Frank Franklin II/The Associated Press
Peng Shuai of China celebrates after defeating Agnieszka Radwanska of Poland during their match at the 2014 U.S. Open tennis tournament in New York, August 27, 2014.MIKE SEGAR/Reuters
Ivan Dodig, of Croatia, serves against Feliciano Lopez, of Spain, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Kathy Willens/The Associated Press
Feliciano Lopez, of Spain, right, returns a shot at the net against Ivan Dodig, of Croatia, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Kathy Willens/The Associated Press
A tennis fan watches play between Feliciano Lopez, of Spain, and Ivan Dodig, of Croatia, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Kathy Willens/The Associated Press
Marin Cilic of Croatia signs autographs after Marcos Baghdatis of Cyprus retired from their match at the 2014 U.S. Open tennis tournament in New York, August 27, 2014.MIKE SEGAR/Reuters
Lleyton Hewitt of Australia hits a return to Tomas Berdych of the Czech Republic during their match at the 2014 U.S. Open tennis tournament in New York, August 27, 2014.EDUARDO MUNOZ/Reuters
Ivan Dodig, of Croatia, leans on the net as he forfeits the match to Feliciano Lopez, of Spain, because of injury in the fifth set during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Kathy Willens/The Associated Press
Angelique Kerber, of Germany, returns a shot against Alla Kudryavtseva, of Russia, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Frank Franklin/The Associated Press
Spectators watch play between Lleyton Hewitt, of Australia, and Tomas Berdych, of the Czech Republic, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Matt Rourke/The Associated Press
Tomas Berdych, of the Czech Republic, serves against Lleyton Hewitt, of Australia, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Matt Rourke/The Associated Press
Simona Halep, of Romania, returns a shot against Jana Cepelova, of Slovakia, during the second round of the 2014 U.S. Open tennis tournament, Wednesday, Aug. 27, 2014, in New York.Elise Amendola/The Associated Press