AC Milan coach Clarence Seedorf gives the thumbs up sign prior to the start of a Serie A soccer match between AC Milan and Hellas Verona, at the San Siro stadium in Milan, Italy, Sunday, Jan.19, 2014. (AP Photo/Luca Bruno)
Napoli's Gonzalo Higuain scores on a penalty during the Serie A soccer match between Bologna and Napoli at Renato Dall' Ara stadium in Bologna, Italy, Sunday, Jan.19, 2014. (AP Photo/Studio FN)
Napoli's Gonzalo Higuain goes for an acrobatic kick during a Serie A soccer match between Bologna and Napoli at the Renato Dall'Ara stadium in Bologna, Italy, Sunday, Jan. 19, 2014. (AP Photo/Studio FN)
Flavia Pennetta of Italy celebrates after winning over Angelique Kerber of Germany during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Eugene Hoshiko)
Flavia Pennetta of Italy celebrates after winning over Angelique Kerber of Germany during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Aaron Favila)
Fabio Fognini of Italy reacts after losing a point durring his fourth round match against Novak Djokovic of Serbia at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Aaron Favila)
Novak Djokovic of Serbia, left, bumps into Fabio Fognini of Italy at the net, after his fourth round win at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Andrew Brownbill)
Novak Djokovic of Serbia celebrates his win over Fabio Fognini of Italy during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Eugene Hoshiko)
Novak Djokovic of Serbia, right, shakes hands with Fabio Fognini of Italy after Djokovic won their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Eugene Hoshiko)
Novak Djokovic of Serbia celebrates his win over Fabio Fognini of Italy during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Eugene Hoshiko)
Serbia's Novak Djokovic impersonates his coach and former Grand Slam champion Boris Becker's service action following his fourth round win over Italy's Fabio Fognini at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014. (AP Photo/Eugene Hoshiko)
Novak Djokovic of Serbia hits a forehand return to Fabio Fognini of Italy during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Aaron Favila)
Flavia Pennetta of Italy makes a backhand return to Angelique Kerber of Germany during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Aaron Favila)
Angelique Kerber of Germany makes a forehand return to Flavia Pennetta of Italy during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2014.(AP Photo/Eugene Hoshiko)