Roger Federer of Switzerland, right, and Rafael Nadal of Spain walk during the change of end in their semifinal at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2014. (AP Photo/Andrew Brownbill)
Roger Federer of Switzerland speaks during a press conference after his semifinal loss to Rafael Nadal of Spain at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2014. (AP Photo/Aijaz Rahi)
Roger Federer of Switzerland speaks during a press conference after his semifinal loss to Rafael Nadal of Spain at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2014. (AP Photo/Aijaz Rahi)