Serbia

f183a68840f60802490f6a70670051e8.jpg

Spectators watch the second round match between Kei Nishikori of Japan and Dusan Lajovic of Serbia at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 16, 2014. (AP Photo/Shuji Kajiyama Shuji)

54b9843d1dd9f502480f6a706700ddf1.jpg

Former Grand Slam champion Boris Becker of Germany looks down onto Rod Laver Arena as he watches defending champion Novak Djokovic of Serbia in his match against Leonardo Mayer of Argentina at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)

8bf785d51d85f302480f6a706700fb55.jpg

Novak Djokovic of Serbia lies on the court after falling during his second round match against Leonardo Mayer of Argentina during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)

7a5b04881db5f402480f6a7067002cdb.jpg

Novak Djokovic of Serbia waits in his seat during break in his second round match against Leonardo Mayer of Argentina at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)

ce125a461d68f302480f6a706700ce30.jpg

Serena Williams of the United States waves to the crowd after defeating Vesna Dolonc of Serbia in their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)