Djokovic Already in Serbia for Davis Cup

He has to be tired, both physically and mentally.  Add some jet lag to the equation, and the pressure of representling your country in the Davis Cup Semi-finals.

It doesn't matter to Novak Djokovic, who is fresh off his U.S. Open loss to Raf Nadal on Monday.  He will be front and center to take on the Czechs in Belgrade.

"Yes, I am exhausted because it's not the easiest thing in the world to recover from playing the entire U.S. Open and traveling back east but I have to adjust as quickly as I can," Djokovic told a news conference after Thursday's draw.

"We can't wait for the tie to begin and I am sure I will be able to beat the fatigue because our motivation and desire to reach the final are huge," said Djokovic, who takes on Radek Stepanek in the opening singles rubber Friday.

Serbia's Janko Tipsarevic takes on Tomas Berdych in the other singles rubber Friday, while Nenad Zimonjic and Viktor Troicki face the Czech duo of Jan Hajek and Ivo Minar in Saturday's doubles.

Djokovic plays Berdych and Tipsarevic is up against Stepanek in Sunday's reverse singles.