Novak Djokovic of Serbia returns the ball to Vasek Pospisil of Canada during their Davis Cup semifinal tennis match in Belgrade, Serbia, Sept. 13, 2013. (Xinhua/Borislav Zdrinja)
Novak Djokovic of Serbia reacts during a press conference after his victory over Vasek Pospisil of Canada at the Davis Cup semifinal tennis match in Belgrade, Serbia, Sept. 13, 2013. (Xinhua/Borislav Zdrinja)
Milos Raonic of Canada returns a ball to Janko Tipsarevic of Serbia during their Davis Cup semifinal tennis match in Belgrade, Serbia, Sept. 13, 2013. (Xinhua/Borislav Zdrinja)
Milos Raonic of Canada returns a ball to Janko Tipsarevic of Serbia during their Davis Cup semifinal tennis match in Belgrade, Serbia, Sept. 13, 2013. (Xinhua/Borislav Zdrinja)
