Santos had his contract selected from Triple-A Buffalo on Wednesday.
Santos was added to the 40-man roster alongside Rhiner Cruz. On the flip side, Tim Mayza was optioned to the minors and Preston Guilmet was designated for assignment to make room. Across 17 appearances with Buffalo this year, Santos has logged a 2.52 ERA and 36:12 K:BB over 39.1 innings. He will likely serve in low-leverage situations for the Blue Jays while with the team.