With participation in next year's World Group on the line, Roger Federer will make his 2007 debut for Switzerland at the Czech Republic. The best-of-five series starts Friday, with the draw scheduled for tomorrow.

Novak Djokovic, who lost to Federer in the U.S. Open final earlier this month, will also play when Serbia hosts 28-time champion Australia in another playoff.

"After 15, 20 years, we've got a chance to get to the World Group," the third-ranked Djokovic said.

Also, four-time Wimbledon semifinalist Tim Henman will be playing his last competitive matches when Britain hosts Croatia at the All England Club.

In the semifinals, the 31-time champion United States visits Sweden and defending champion Russia hosts Germany.

On Sept. 9, Federer won his fourth straight U.S. Open and 12th Grand Slam title. Just like the last couple of years, the top-ranked Swiss skipped the early rounds of the Davis Cup but is returning to help his country in the playoffs.

"I'm really looking forward to the Davis Cup weekend again," said Federer, who won three major titles this year and reached his second straight French Open final. "I haven't had it for a year. I'm very excited."

Lleyton Hewitt, a former top-ranked player and two-time Grand Slam champion, will lead Australia against the Serbs and Djokovic.

"I haven't played too many relegation matches in my career," Hewitt said. "We're going to go in as the underdogs, but we'll see what happens."

The other playoffs include Austria vs. Brazil; Peru vs. Belarus; Israel vs. Chile; Japan vs. Romania; and Slovakia vs. South Korea.

The winners of the eight playoffs will play in next year's World Group along with the eight quarterfinalists.

The Americans have won the most Davis Cup titles, but the last title came in 1995.

"I'm just worried about our guys playing well," United States captain Patrick McEnroe said. "I think if we're ready to play, play the best we can play, I feel pretty good about our chances."

The Swedes, however, are 3-1 against the Americans in Goteborg, where they will play on indoor carpet this weekend.

"I like the surface. I feel like it's a good surface for us actually," said Andy Roddick, who will team with James Blake and twins Bob and Mike Bryan for the Americans. "It's quick, but I think there's been quicker surfaces. You know, you're still able to set up, hit balls, play from the baseline."

Sweden will be led by 2002 Australian Open champion Thomas Johansson, Jonas Bjorkman, Joachim Johansson and Simon Aspelin.

Russia, which beat Argentina to win the 2006 title, will have fourth-ranked Nikolay Davydenko when it faces Germany on clay in Moscow.