Toronto selected the reliever's contract from Triple-A Buffalo on Saturday and optioned Kyle Drabek in a corresponding roster move.
Santos was excited to be back after what he called a four-week refresher with the Bisons.
"It was good," said Santos, who pitched 10 2/3 innings (11 appearances) without allowing a run with Buffalo, earning a win and two saves. "I think a lot of it has to do with consistently throwing, having an outing pretty much every other day. Getting into a rhythm ... get some momentum and build on it."
The Blue Jays designated the right-hander after he struggled through 24 games, posting an 0-2 record with a 7.78 ERA. Santos cleared waivers and headed to Buffalo to with the goal of working his way back to Majors as quickly as possible.
Santos said his time at Triple-A was a "humbling experience," and it was a challenge he hadn't been faced with in a long time. But it was an opportunity to appreciate life in the Majors, and it motivated him work his way back.
"All I could control was how I was throwing, and I knew the better I threw, the more pressure I could put on the team as far as coming back up," Santos said. "Try not to worry about it, and just worry about throwing."
Drabek, meanwhile, made two relief appearances for the Blue Jays, allowing two hits and walking two over three innings. He's 7-7 with a 4.00 ERA in 29 games (13 starts) with the Bisons this season.
Jamie Ross is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.