Spain has history on its side in its Davis Cup semifinal against the United States.

The United States has won in Spain only once and that was 40 years ago, while Spain's comfortable wins this year over Kazakhstan and Austria extended its 12-year unbeaten streak at home to 23 ties, all on clay. Spain is the defending champion and also won in 2008 and 2009.

Spain will face the United State this weekend on clay in Gijon, the port city on the Atlantic north coast. In the other semifinal, the Czech Republic will play Argentina in Buenos Aires, also on clay.

With Rafael Nadal still rehabbing the injured left knee that kept him out of the Olympics and U.S. Open, Spain will be led again by David Ferrer, who is undefeated in Davis Cup at home and on clay. Nicolas Almagro is 4-0 in singles cup play this year, and Marcel Granollers and Marc Lopez will be the likely doubles team.

Ferrer starred in the two most recent ties against the U.S., a semifinal win in 2008 and quarterfinal win in Austin, Texas, last year, and said being favored at home meant nothing.

"In Austin they were the favorite and we won. This time, we hope we will win again," he said.

The U.S. has surprised this year, with wins in Switzerland and France, both on clay. John Isner led the way with victories over Roger Federer and Jo-Wilfried Tsonga.

The Bryan twins, formidable in Davis Cup, are back in doubles, leaving the pressure on Isner to win his singles against Almagro on Friday and Ferrer on Sunday. Isner has losing records against both. Sam Querrey, who made his cup debut in the 2008 semifinal, was brought in as No. 2 for newcomer Ryan Harrison.

"I know our team is going to go in there believing we can win. We've had two already tough wins on the road so far," Isner said. "We really do believe that we can beat Spain and that we can win the Davis Cup."

Argentina's hopes of beating the Czechs rest on the enduring fitness of former U.S. Open champion Juan Martin del Potro.

Del Potro came out of his U.S. Open quarterfinal loss with a wrist injury and a wrist specialist's recommendation to rest it for 15 days, "but I'll do the impossible to play against Czech Republic," he tweeted.

He practiced Wednesday and is expected to play. Already without David Nalbandian, sidelined by a strained chest muscle that forced him out of the U.S. Open, Argentina wouldn't have the firepower without del Potro to stave off Czech stalwarts Tomas Berdych and Radek Stepanek.

Berdych hasn't lost in Davis Cup for 18 months, and won three points in a 4-1 win over Serbia in the quarterfinals.