Varsho batted .214 with 18 home runs and 58 RBIs in 136 games last season before undergoing season-ending surgery on his right shoulder. He also earned his first Gold Glove Award.
The 28-year-old served as DH during spring training but did not play in the field and opened the regular season on the IL.
Right-handed pitcher Casey Lawrence, who was claimed off waivers from the Seattle Mariners on Monday, will also be active for the game.
Toronto (13-15) will look to bounce back after losing both games of a doubleheader Sunday against the New York Yankees.
Watch the Blue Jays host the Red Sox live on Sportsnet and Sportsnet+ starting at 7 p.m. ET / 4 p.m. PT.