By Martyn Herman
LONDON (Reuters) - With precious little time to rest after their brutal U.S. Open final, world number one Novak Djokovic and Rafa Nadal will be energized by national pride this weekend as they lead their countries into battle in the Davis Cup semi-finals.
Djokovic, winner of three of the year's four majors in a stupendous season that has gone off the scale, will enjoy a deafening reception in the cavernous Belgrade Arena where Serbia host Argentina.
In a Cordoba bull ring, Nadal will have the perfect stage to vent the frustration of his defeat by Djokovic in New York, as Spain host last year's runners-up France seeking to banish the memory of a 5-0 thrashing last year.
Neutrals and probably the International Tennis Federation (ITF) will already be eagerly anticipating a potential Djokovic v Nadal showdown in the final but the wily Argentines and flamboyant French will be no pushovers.
"The energy coming from Novak rubs on to the team and it is the best form of motivation."
Twelve months ago after losing to Nadal in the U.S. Open final Djokovic could hardly have imagined what was going to happen to him in 2011.
Playing like a man possessed he has amassed a 64-2 record, surging clear at the top of the rankings and on current form, looks almost unbeatable.
The 24-year-old, who owns a chain of restaurants in the Serbian capital, one of which is just across the street from the Belgrade Arena where Serbia have never lost a Davis Cup tie, said the spark for his explosive improvement was last year's thrilling final against France.
Argentina are the only one of the semi-finalists not to win the trophy, but have a powerful line-up themselves with 2009 U.S. Open champion Juan Martin del Potro and David Nalbandian joined by Juan Ignacio Chela and Juan Monaco.
Captain Tito Vazquez acknowledged his side face a huge challenge.
"It is obvious that Serbia, being the current champions and undefeated at home, on top of having the No. 1, Novak Djokovic, in the best year of his career, is a difficult rival, " he said. "Home advantage in Davis Cup is always important and this time will not be any different, no doubt about it."
Since the break-up of the former Yugoslavia, Serbia have never played Argentina but the other semi-final is a familiar fixture on the Davis Cup circuit.
They are meeting for the eighth time and Spain, winners in 2000, 2004, 2008 and 2009, will still be smarting from defeat in the quarter-finals last year in Clermont-Ferrand.
Nadal did not play in the previous round against the United States but with France boasting Jo-Wilfried Tsonga, Gael Monfils, Gilles Simon and Richard Gasquet, all of them ranked in the world's top 15, the Mallorcan's availability is a massive boost for captain Albert Costa.
The specially built claycourt at the Plaza de Toros de los Califas bull ring will give the Spaniards a distinct advantage with world number five David Ferrer, who like Nadal has never lost a Davis Cup rubber on the red dirt, a formidable No.2.
"I'm tired for sure, I played a long match Monday," Nadal, who arrived on a private jet, told the ITF referring to the U.S. Open final which was delayed by 24 hours due to bad weather. "It's not a mental problem to play, it's more of a physical problem but I'm ready to play for my country."
Away from the semi-finals, world number three Roger Federer will play for Switzerland in Sydney against Australia in a playoff tie, while Japan are attempting to reach the World Group for the first time since 1985 when they host India.
(Additional reporting by Zoran Milosavljevic; editing by Pritha Sarkar)