Li Na of China serves to Belinda Bencic of Switzerland during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Li Na of China makes a forehand return to Belinda Bencic of Switzerland during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Novak Djokovic of Serbia waves to the crowd after winning his second round match against Leonardo Mayer of Argentina at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
David Ferrer of Spain changes his shirt during his second round match against Adrian Mannarino of France at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Rick Rycroft)
Adrian Mannarino of France makes a backhand return to David Ferrer of Spain during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Rick Rycroft)
David Ferrer of Spain makes a forehand return to Adrian Mannarino of France during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Rick Rycroft)