The Padres optioned Gillaspie to Triple-A El Paso on Saturday.
Gillaspie had been competing for a middle-relief spot in the Padres' bullpen, but he will miss the cut after giving up two runs over four innings while striking out three batters in exhibition play. The 26-year-old righty owns a 4.10 career ERA in the big leagues and could rejoin the Padres should the team run into depth problems during the season.