With Serbia hit by injuries and suspensions, Novak Djokovic will carry the burden for his country when it plays defending champion Czech Republic in the Davis Cup final. The second-ranked Djokovic is on a 22-match unbeaten run, and now must do what he has done numerous times before - win both singles matches to give the Serbs a chance in the best-of-five series starting Friday. On Thursday, Serbia's Janko Tipsarevic was ruled out of the final with a heel injury. Countryman Viktor Troicki, the star of the 2010 Davis Cup home victory over France, is out because of a 12-month suspension for skipping a blood test in April. More...