Davis Cup preview: Djokovic, Nadal ready?

The Davis Cup World Group semifinals begin on Friday. Serbia will play host to Argentina and France will visit Spain, with the winners meeting in the finals in early December. Here's our preview of those matchups as well as a look at other Davis Cup action this weekend.

• Gimpy gladiators: U.S. Open champion Novak Djokovic of Serbia and runner-up Rafael Nadal of Spain come into their ties hobbled by injury and fatigue. Djokovic was still doing his victory tour in New York when Nadal landed in Spain, and while the Serb is surely riding the emotional high of his third Grand Slam title of the year, he is also worn down and nursing a back injury that required a medical timeout in the final. As for Nadal, he acknowledged being physically exhausted from his New York campaign.  "I am trying for my country, but it's tough," Nadal told reporters. "For me it's not a mental problem, it's a physical problem. I am ready to play mentally, but physically [the last] two and a half weeks was hard."

• Lord, I was born a gamblin' man: As of Thursday, Serbian captain Bogdan Obradovic had nominated Djokovic to play the opening singles match against Argentina's David Nalbandian. Spanish captain Albert Costa also tapped Nadal for the first singles, against France's Richard Gasquet. But the status of the top two players in the world was still in question. Despite the nominations, Davis Cup captains can change lineups up to an hour before a match.

The question is whether Serbia and Spain gamble on benching their top dogs in hopes of still salvaging at least a point on Friday. It's less of a risk for Spain on the first day, as France will be playing without Jo-Wilfried Tsonga (scheduled to play doubles with Michael Llodra on Saturday) and Gael Monfils (knee injury). And playing on clay surely weighs heavily in Spain's favor; Nadal, David Ferrer and Fernando Verdasco are all better on the surface than Gilles Simon, Richard Gasquet and Llodra, especially at home.

Serbia has a tougher decision to make. Without Djokovic, Viktor Troicki and Janko Tipsarevic would be asked to face Nalbandian and Juan Martin del Potro. Should Serbia lose both matches, which is a possibility on paper, it would be putting all its hopes to survive on Saturday's doubles match. Is Serbia really willing to risk losing a shot at defending its title without Djokovic ever taking the court in singles? Of course, the stat sheet should give Obradovic some comfort: Serbia is on a seven-match winning streak and has lost only three times at home since 1995. On the other hand, Argentina is 0-6 in Davis Cup semifinals on foreign soil.

• David Nalbandian, Davis Cup hoss: Before Andy Murray emerged, most tennis observers tagged Nalbandian as the best player to never win a major. The raw talent is there, though the work ethic hasn't always been. While inconsistent in regular Tour events and Grand Slams, the Argentine's willingness to compete for his country has been constant. Regardless of his form, Nalbandian always shows up for Davis Cup, and he's made it his mission to bring the Davis Cup to Argentina for the first time.

That singular focus hasn't always been a good thing. Playing at home against Nadal-less Spain in 2008, Argentina was poised to finally win the Davis Cup. But Spain thrived as an underdog, and as the Cup began to slip away from Argentina, discord grew within the ranks, most notably between Nalbandian and del Potro. The two are reunited now and must know that putting aside their differences is the only way they'll pull off the upset in an indoor hardcourt in Belgrade.

• You guys know he's not Australian, right?: The Australians rolled out the red carpet for Roger Federer's arrival. Federer, who rarely plays Davis Cup, will lead Switzerland against Australia in Sydney in a World Group playoff. The winner will be promoted to World Group next year, while the loser faces relegation to the Zonal Group. With Federer joining Stanislas Wawrinka, this is Switzerland's tie to win against the likes of Lleyton Hewitt and Bernard Tomic.

If the Aussies weren't already being so hospitable, they even chose grass as the surface. Yes, the grass upon which Federer has won six Wimbledon titles. Are the Aussies putting stock in the fact that Lleyton Hewitt defeated Federer in their last meeting on grass (last year in Germany)? Or perhaps they think the grass will neutralize Wawrinka? Or maybe they've just given up want to see a good show by Fed? I mean, I get wanting to be good hosts, but this might be a bit much.

• Promotion and relegation: Speaking of the World Group playoffs, 16 teams are competing for a spot in the World Group in 2012. I love the concept of promotion and relegation, which is something we don't see in American sports. It keeps the competition relevant and makes every tie important for the players. Here are the matchups:

Czech Republic vs. Romania

Croatia vs. South Africa

Switzerland vs. Australia

Israel vs. Canada

India vs. Japan

Austria vs. Belgium

Russia vs. Brazil

Chile vs. Italy

Look for the Czech Republic, Croatia and Switzerland to secure spots, but the rest of the ties should be tightly contested. Canada is hoping Milos Raonic, who has been sidelined with a hip injury since Wimbledon, can return against Israel. As for the rest, I like India, Austria, Russia and Chile to round out the bunch.

Keep an eye on the Great Britain vs. Hungary tie as well. With Murray in the mix, Great Britain should roll and gain promotion to Group I next year. It'll take a couple of years, but I'm still waiting (hopelessly hoping?) for the day when Serbia, Spain, Switzerland and Great Britain can battle it out in World Group.

Bring on the rematch