The Blue Jays acquired the 25-year-old from St. Louis in a three-team trade that included the White Sox in July after the 2005 first-round pick struggled at the plate and clashed with the Cardinals over his choice to be coached by his father rather than hitting instructor Mark McGwire.
Rasmus hit .225 with 14 homers and 53 RBIs last year, a drop off after hitting 23 homers for St. Louis in 2010. He has hit .253 with 53 homers and 171 RBIs in three major league seasons.
Rasmus made $443,000 last year and filed for arbitration Friday.
Toronto announced the deal Sunday and still has five players who have filed for arbitration.