Still riding a wave of euphoria after their Australian Open success, Novak Djokovic and Nenad Zimonjic could turn out to be unwelcome guests in Moscow for Serbia's Davis Cup tie against Russia.
Russia have proved to be the recent powerhouse in the men's team competition, winning the title in 2006 and finishing runners-up to the United States last December, but their chances of making it past even the first round in 2008 look rather slim.
Facing an in-form team spearheaded by newly crowned Australian Open men's champion Djokovic and mixed doubles winner Zimonjic, Russia will enter the hardcourt tie as underdogs even though they enjoy home advantage.
While Serbia can also count on the services of Janko Tipsarevic, who stretched world number one Roger Federer to five sets in the third round at Melbourne Park, Russia will be relying on a trio who have failed to shine in recent months.
World number four Nikolay Davydenko will be joined by Mikhail Youzhny and the more unpredictable Marat Safin, now ranked 61st in the world.
The tie is the most intriguing of eight world group first-round showdowns taking place from Friday to Sunday.
The US have barely had two months to savour their latest triumph, and 32nd in total, before having to fly back to Europe to begin their title defence in Austria.
Captain Patrick McEnroe has chosen to keep faith with a winning combination with doubles specialists Mike and Bob Bryan joining forces with Andy Roddick and James Blake.
The Americans have won both of their previous meetings against Austria but could find things are not quite to their liking in Vienna, where the hosts have opted for an indoor clay court.
INSTIGATE DOWNFALL
Neither Roddick nor Blake feel at home on clay -- neither survived the first round at Roland Garros in 2007 -- and the slow surface could instigate their downfall.
"This is going to be a tough match against an Austria team who have very good players and playing away and on clay is always difficult," McEnroe told reporters.
Rafael Nadal and David Ferrer have excused themselves from Spain's long haul trip to Peru. Despite the absence of their top five players, the twice former champions should still manage to roll over a team making their world group debut.
While Feliciano Lopez is the lowest ranked player, at 37, in Emilio Sanchez's squad, a full-strength Peru side will be led by world number 120 Luis Horna in Lima.
British coach John Lloyd could have done with having Sanchez's problems.
After the withdrawal of Andy Murray, Lloyd's hopes of avoiding a whitewash against a formidable Argentine team on their favoured clay surface in Buenos Aires rests with world number 188 Alex Bogdanovic.
Argentine coach Alberto Mancini made no secret what his team will be aiming for.
"We want get a strong start and end the tie as quickly as possible," Mancini said.
Muhammad Ali lookalike Jo-Wilfried Tsonga, runner-up to Djokovic in Melbourne and making his Cup debut, will be the main attraction in Sibiu, where France will be favourites to extend their 7-1 record against Romania.
Jonas Bjorkman, who welcomed the arrival of a baby daughter last month, is banking on his parenting skills to guide Sweden's victory charge against Israel on the outskirts of Tel Aviv.
"I'm fitter than ever, I have been changing diapers really well so my reflexes are very good," joked the 35-year-old doubles specialist.
In the remaining tussles, the Czech Republic host Belgium, while Germany should have little trouble dispatching South Korea.