
Novak Djokovic of Serbia serves to Gilles Simon of France during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 24, 2016.(AP Photo/Rick Rycroft)
Novak Djokovic of Serbia serves to Gilles Simon of France during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 24, 2016.(AP Photo/Rick Rycroft)