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)
Rafael Nadal of Spain, right, is congratulated by Roger Federer of Switzerland at the net after Nadal won their semifinal at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2014.(AP Photo/Rick Rycroft)
Rafael Nadal of Spain celebrates after defeating Roger Federer of Switzerland during their semifinal at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2014.(AP Photo/Aijaz Rahi)
Rafael Nadal of Spain celebrates after defeating Roger Federer of Switzerland during their semifinal at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2014.(AP Photo/Aaron Favila)