The Blue Jays selected McCoy's contract from Triple-A Buffalo on Tuesday.
The 28-year-old was acquired by Toronto from Seattle in exchange for Trent Thornton in late July and will now have the chance to make his major-league debut. McCoy has a .572 OPS in 21 games since joining Buffalo but fared better with the Mariners' Triple-A affiliate with a .737 OPS. He'll provide some defensive versatility after Bo Bichette (quadriceps) landed on the injured list but may not see much playing time.