Australian Open: First Grand Slam of the year

Defending champions Serbia's Novak Djokovic and Victoria Azarenk of Belarus pose with their trophies beside a Melbourne tram prior to the official draw at the Australian Open tennis championship in Melbourne, Australia. (AP Photo)

Serbia's Novak Djokovic makes a forehand return to Juan Monaco of Argentina during an exhibition match at the Kooyong Classic ahead of the Australian Open tennis championship in Melbourne, Australia. (AP Photo)

Serena Williams of the U.S. celebrates after winning the women's singles final match against Victoria Azarenka of Belarus 6 4, 7 5 during the Brisbane International tennis tournament in Brisbane, Australia, Saturday. (AP Photo)

Victoria Azarenka of Belarus plays a shot in her match against Casey Dellacqua of Australia during the Brisbane International tennis tournament in Brisbane, Australia. (AP Photo)

Roger Federer of Switzerland plays a shot in his match against Jarkko Nieminen of Finland during the Brisbane International tennis tournament in Brisbane, Australia. (AP Photo)

Lleyton Hewitt of Australia throws his racket in his semi final match against Kei Nishikori of Japan during the Brisbane International tennis tournament in Brisbane, Australia. (AP Photo)

Kei Nishikori of Japan uses an ice pack to cool down in his semifinal match against Lleyton Hewitt of Australia during the Brisbane International tennis tournament in Brisbane, Australia. (AP Photo)