see more

MELBOURNE, AUSTRALIA - JANUARY 20: Roger Federer of Switzerland serves in his second round match against Alexandr Dolgopolov of Ukraine during day three of the 2016 Australian Open at Melbourne Park on January 20, 2016 in Melbourne, Australia. (Photo by Mark Kolbe/Getty Images)

MELBOURNE, AUSTRALIA - JANUARY 20:  Roger Federer of Switzerland serves in his second round match against Alexandr Dolgopolov of Ukraine during day three of the 2016 Australian Open at Melbourne Park on January 20, 2016 in Melbourne, Australia.  (Photo by Mark Kolbe/Getty Images)