Roger Federer During Practice Session - Australian Open 2013 at Melbourne

Roger Federer practices a serve before the 2013 Australian Open. Tuesday, 8 January, 2013. © Ben Solomon

Roger Federer speaks with some kids during his practice session at the 2013 Australian Open. Tuesday, 8 January, 2013. © Ben Solomon

Roger Federer of Switzerland reacts as Lleyton Hewitt of Australia walks past during practice ahead of the 2013 Australian Open at Melbourne Park on January 8, 2013 in Melbourne, Australia.