Rafael Nadal is returning to Spain's Davis Cup team after a two-year absence for a lower-tier series against Denmark.
It will be the eighth-ranked Nadal's second Davis Cup appearance in the last four years.
Spain needs to win the best-of-five series to remain in Group 1 and avoid a relegation playoff against Sweden.
Also called up by coach Conchita Martinez on Tuesday were seventh-ranked David Ferrer, Roberto Bautista, Fernando Verdasco and David Marrero.
Nadal is enduring one of its worst years on tour and is coming off early elimination at the U.S. Open. The last time he played in the Davis Cup was against Ukraine in the 2013 World Group playoff in Madrid.
Ferrer hasn't played in the Davis Cup in three years, the last time in the 2012 final against the Czech Republic.
Ferrer has a 23-4 record in the Davis Cup, while Nadal has won 21 matches in a row since losing in his 2004 debut. Ferrer and Nadal helped Spain win four of its last five Davis Cup titles.
"We have a spectacular team," Martinez said. "It's always dangerous to play away from Spain, where the conditions will obviously favor the home team."
Denmark picked a hard court to try to take away the advantage of the Spaniards, who traditionally play well on clay.
Spain, coming off a 3-2 loss to Russia, is not in the competition's top tier for the first time since 1996. The five-time champions won't be able to return to the World Group before 2017.