MELBOURNE, AUSTRALIA - JANUARY 13: Novak Djokovic of Serbia hits a forehand during a practice session ahead of the 2016 Australian Open at Melbourne Park on January 13, 2016 in Melbourne, Australia. (Photo by Graham Denholm/Getty Images)
MELBOURNE, AUSTRALIA - JANUARY 13: Novak Djokovic of Serbia hits a forehand during a practice session ahead of the 2016 Australian Open at Melbourne Park on January 13, 2016 in Melbourne, Australia. (Photo by Graham Denholm/Getty Images)