The best-of-five series will be played outdoors on a red clay court in Castellon, Spain. The series winner moves to the Davis Cup semifinals Sept. 14-16 against either France or the United States.
Almagro, No. 12 in the world rankings, goes against No. 21-ranked Jurgen Melzer in the first of two singles matches Friday. The second match features fifth-ranked Spaniard David Ferrer taking on Andreas Haider-Maurer, who is No. 139 in the world.
Saturday's schedule calls for a doubles match with Austrians Oliver Marach and Alexander Peya going against Marcel Granollers and Marc Lopez. All of the players are in the Top 40 of the ATP doubles rankings.
The reverse singles schedule Sunday has Ferrer playing Melzer and Almagro going Haider-Maurer.