Serena Williams at a press conference WTA Tennis Championships in Doha Qatar

Serena Williams of the United States is seen in front of a poster of herself at a press conference ahead of the WTA Tennis Championships in Doha, Qatar.

Serena Williams reacts after returning a ball to Russia Nadia Petrova

USA's Serena Williams reacts after returning a ball to Russia's Nadia Petrova during their match in the third round of the China Open tennis tournament in Beijing, China

US Serena Williams celebrates upon defeating Russia Ekaterina Makarova

US Serena Williams celebrates upon defeating Russia's Ekaterina Makarova during second round of the China Open tennis tournament in Beijing, China.

Serena Williams returns shot against Kaia China Open Tennis tournament in Beijing China

Serena Williams of U.S. returns a shot against Kaia Kanepi of Estonia during the China Open Tennis tournament in Beijing, China