Media reports said Almagro, who reached the quarterfinals of the Australian Open, has a leg injury.
Garcia-Lopez joins fellow newcomer Albert Ramos and doubles team Marcel Granollers and Marc Lopez for the series in Vancouver on Feb. 1-3.
This means the five-time champions will be without their top three players, with Rafael Nadal injured and David Ferrer sitting out the round.
With Nadal out, Ferrer led Spain to last year’s final and lost to the Czech Republic.
Canada will be led by 15th-ranked Milos Raonic.