The Blue Jays optioned Santos to Triple-A Buffalo on Sunday, Shi Davidi of Sportsnet.ca reports.
Santos was used out of the bullpen both of the previous two days and accrued 34 pitches, making it unlikely that he would be available in relief for the next day or two. As a result, the Blue Jays decided to send him back to the minors in favor of a fresh bullpen arm in Justin Shafer, who was called up from Triple-A in a corresponding move.