The pressure will be on Novak Djokovic to lead Serbia to a Davis Cup title in front of the home fans. Janko Tipsarevic, the country's No. 2 player, is doubtful against defending champion Czech Republic because of a chronic heel injury. If Tipsarevic sits out, doubles specialist Nenad Zimonjic could step in, though he hasn't played a meaningful Davis Cup singles match since 2008. He has won his last four tournaments, including the ATP Finals in London, where he beat top-ranked Rafael Nadal 6-3, 6-4 in the final Monday. More...