Serena Williams returns a shot to Victoria Azarenka, of Belarus, during the women's singles final of the 2013 U.S. Open tennis tournament, Sunday, Sept. 8, 2013, in New York. (AP Photo/David Goldman)
Serena Williams reacts after a point against Li Na, of China, during the semifinals of the 2013 U.S. Open tennis tournament, Friday, Sept. 6, 2013, in New York. (AP Photo/David Goldman)
Serena Williams pumps her fists after a point against Sloane Stephens during the fourth round of the 2013 U.S. Open tennis tournament, Sunday, Sept. 1, 2013, in New York. (AP Photo/David Goldman)
Serena Williams gestures to the crowd after winning her second round match against Galina Voskoboeva, of Kazakhstan, at the 2013 U.S. Open tennis tournament, Thursday, Aug. 29, 2013, in New York. (AP Photo/Kathy Willens)