Spain has won three of the last five Davis Cup titles and was the runner-up last year after a tight 3-2 final with the Czech Republic.
Spain in recent years would often turn to Nadal or David Ferrer, who this week passed Nadal for the world No. 4 ranking, to spark its Davis Cup team. But Nadal hasn't played since Wimbledon due to injury and Ferrer, who advanced to the Australian Open semifinals, is passing up the Davis Cup first round.
Also missing is No. 11-ranked Nicolas Almagro, who has a leg injury.
Albert Ramos, 51st in the world, and No. 34 Marcel Granollers have been selected to handle singles duties for Spain as the team heads to Vancouver, British Columbia, for the best-of-five series. The Canadians have selected a hard indoor court for the surface.
Ramos will go against world No. 15 Milos Raonic in the series opener Friday with Granollers facing Frank Dancevic, 166th in the world, in the second match. They are to swap opponents for matches Sunday.
There is a doubles match set for Saturday with Canadians Daniel Nestor and Vasek Pospisil meeting Granollers and Guillermo Garcia-Lopez.
The winner of the series in Vancouver goes to the April 5-7 Davis Cup quarterfinals against either Croatia or Italy.