MELBOURNE, AUSTRALIA - JANUARY 22: Novak Djokovic of Serbia hits a return in his third round match against Andreas Seppi of Italy during day five of the 2016 Australian Open at Melbourne Park on January 22, 2016 in Melbourne, Australia. (Photo by Recep Sakar/Anadolu Agency/Getty Images)

MELBOURNE, AUSTRALIA - JANUARY 22: Novak Djokovic of Serbia hits a return in his third round match against Andreas Seppi of Italy during day five of the 2016 Australian Open at Melbourne Park on January 22, 2016 in Melbourne, Australia.  (Photo by Recep Sakar/Anadolu Agency/Getty Images)