During his ten-year professional career, Zubillaga played with Real Sociedad and RCD Español. He won the La Liga title in the 1981–82 season with the former team, although he only contributed with eight games (184 minutes, no complete matches). Until 1987, year in which he helped the Basques conquer the Copa del Rey, he never played in more than 18 league matches, and left precisely in that summer.
