Serena Williams of the United States eyes the ball as she returns to Daria Kasatkina of Russia during their third round match at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 22, 2016.(AP Photo/Aaron Favila)
Serena Williams of the United States holds up the trophy after winning the women's singles final against Garbine Muguruza of Spain, at the All England Lawn Tennis Championships in Wimbledon, London, Saturday July 11, 2015. Williams won 6-4, 6-4. (AP Photo/Kirsty Wigglesworth)
Serena Williams of the United States returns a shot to Garbine Muguruza of Spain, during the women's singles final at the All England Lawn Tennis Championships in Wimbledon, London, Saturday July 11, 2015. (AP Photo/Kirsty Wigglesworth)
Serena Williams of the United States talks during a press conference after defeating Garbine Muguruza of Spain in the final of the women's singles final at the All England Lawn Tennis Championships in Wimbledon, London, Saturday, July 11, 2015. (Javier Garcia/Pool Photo via AP) ** FILE **
Serena Williams of the United States returns a shot to Garbine Muguruza of Spain during the women's singles final at the All England Lawn Tennis Championships in Wimbledon, London, Saturday July 11, 2015. (Sean Dempsey/Pool Photo via AP)
Serena Williams of the United States returns a shot to Maria Sharapova of Russia, during the women's singles semifinal match at the All England Lawn Tennis Championships in Wimbledon, London, Thursday July 9, 2015. (AP Photo/Pavel Golovkin)
Serena Williams of the United States returns a shot to Maria Sharapova of Russia during the women's singles semifinal match at the All England Lawn Tennis Championships in Wimbledon, London, Thursday July 9, 2015. (AP Photo/Alastair Grant)
Serena Williams of the United States celebrates winning a point againstVictoria Azarenka of Belarus during their singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday July 7, 2015. (AP Photo/Pavel Golovkin)
Serena Williams of the United States celebrates a point during the women's singles first round match against Margarita Gasparyan of Russia at the All England Lawn Tennis Championships in Wimbledon, London, Monday June 29, 2015. (AP Photo/Pavel Golovkin)
Serena Williams [Tennis Champion] Serena Williams was raised as a Jehovah’s Witness and continues to adhere to that faith today. Christian Post.com quoted Williams after her 2012 Wimbledon win with, "I want to thank Jehovah for letting me get this far. I almost didn't make it a few years ago, but now I'm here again and it's so worth it."
Serena Williams of the U.S. returns in her semifinal match of the French Open tennis tournament against Timea Bacsinszky of Switzerland at the Roland Garros stadium, in Paris, France, Thursday, June 4, 2015. Williams won in three sets 4-6, 6-3, 6-0. (AP Photo/Francois Mori)
Serena Williams of the U.S. closes an eye as she plays compatriot Sloane Stephens of the U.S. during their fourth round match of the French Open tennis tournament at the Roland Garros stadium, Monday, June 1, 2015 in Paris. (AP Photo/Christophe Ena)
Serena Williams (right) has returned to Indian Wells, California, where in 2001 she was taunted when she won a semifinal match against sister Venus when and injury forced Venus to withdraw. (Associated Press)
Serena Williams, above, at the 2015 Australian Open, will play in the BNP Paribas Open in Indian Wells, Calif., next month, ending a personal boycott that began when she was booed at the 2001 event. (AP Photo/Lee Jin-man)
Serena Williams of the U.S. reacts during her singles match against Romania's Simona Halep at the WTA tennis finals in Singapore, Wednesday, Oct. 22, 2014. (AP Photo/Mark Baker)
Serena Williams, reacts after a shot against Caroline Wozniacki, of Denmark, during the championship match of the 2014 U.S. Open tennis tournament, Sunday, Sept. 7, 2014, in New York. (AP Photo/Darron Cummings)
Serena Williams, returns a shot against Ekaterina Makarova, of Russia, during the semifinals of the 2014 U.S. Open tennis tournament, Friday, Sept. 5, 2014, in New York. (AP Photo/Charles Krupa)
Serena Williams, of the United States, returns a shot to Kaia Kanepi, of Estonia, during the fourth round of the 2014 U.S. Open tennis tournament, Monday, Sept. 1, 2014, in New York. (AP Photo/Charles Krupa)
Serena Williams returns to Caroline Wozniacki, from Denmark, during a semifinal match at the Western & Southern Open tennis tournament, Saturday, Aug. 16, 2014, in Mason, Ohio. (AP Photo/David Kohl)
Serena Williams clenches her fist after breaking Ana Ivanovic, from Serbia, in the second set of a final match at the Western & Southern Open tennis tournament, Sunday, Aug. 17, 2014, in Mason, Ohio. Williams won 6-4, 6-1. (AP Photo/Al Behrman)