Santos was designated for assignment by the Blue Jays on Monday, Shi Davidi of Sportsnet.ca reports.
Santos was dropped from the team's 40-man roster to free up a spot for Murphy Smith, whose contract was selected from Triple-A Buffalo in a corresponding roster move. The 27-year-old Santos compiled a solid 2.85 ERA across 41 innings with the Bisons this season, though his 7.20 ERA across 20 big-league innings likely rendered him expendable. He'll likely report back to Buffalo should he pass through waivers untouched.