The hope is that the injury woes are now a thing of the past and Santos can build upon a dominating second half to secure his spot as the reliable late-inning reliever most people expected him to become.
"That to me was a big motivating factor to me coming back," Santos said. "I wanted to prove to myself for the most part -- and then to everybody else -- that I still have the ability to get people out.
"That's what I worked hard for. That's what the light at the end of the tunnel was when I was down in Dunedin, [Fla.], rehabbing almost losing my mind. It's just that [I was] pushing myself, knowing when I did get an opportunity again to try and make the most of it."
Santos has the exact type of skill set most teams look for in an elite setup man or closer. He possesses an overpowering fastball that consistently hits the upper 90s on the radar gun, while his wipe-out slider consistently leads to a high number of strikeouts.
Aside from injuries, Santos' biggest weakness in the past was his erratic command. Even when the California native recorded 30 saves for the White Sox in 2011, he did so while walking 29 batters in 63 1/3 innings. It was a cause for concern, but the numbers looked a lot better when he returned to the Blue Jays in August.
Santos walked just three batters over 21 1/3 innings while posting an impressive 1.69 ERA. He limited the opposition to a paltry .118 batting average and once again secured a spot in late-inning relief despite a bullpen that had become rather crowded with a series of reliable options at manager John Gibbons' disposal.
To a certain extent, the improved command is a byproduct of Santos' refined delivery. If there was any benefit to his extended absence, it was the fact that Santos had the time to work through a series of adjustments and now has a smoother delivery and more refined mechanics on the mound.
"I'm not trying to do too much. I feel like I can locate a lot better, because my delivery is more consistent," Santos said. "By simplifying it, it's easier to repeat that more often, and luckily it's working out for me right now and I'm just on one of those runs.
"I've been fooling around with a lot of different things just to figure out what's best for me. I know everyone's different. It's just a matter of getting into a routine, finding out what works for you and something you can repeat on a consistent basis."
Santos is set to earn $3.75 million next season in the final guaranteed year of a deal he originally signed with Chicago. Toronto then has three options years on his contract valued at a total of $22.75 million, but to a certain extent, how long Santos remains in the fold depends entirely on his performance.
The Blue Jays also have more depth in the bullpen than at any point in the franchise's recent history. Late-inning options include the likes of closer Casey Janssen, All-Stars Steve Delabar and Brett Cecil, Dustin McGowan, Aaron Loup and Neil Wagner.
It's an impressive collection of arms, but then there's also another group of pitchers who are out of options on their contracts. Brad Lincoln, Luis Perez, Jeremy Jeffress, Esmil Rogers and Todd Redmond cannot be sent to the Minors without first being exposed to waivers.
That has led many to believe that Toronto will look to make at least one trade this offseason. The goal would be to use some of the club's pitching depth to fill another hole on the roster, and the fact that a reliable setup man or closer could be moved can be attributed as much to Santos' recent run of success and health than anything else.
"I wanted to see him put together a full season, but he definitely looked like the guy we traded for," general manager Alex Anthopoulos said at the end of the season.
"He looked outstanding. His slider to me is as good as you're going to find, and he just looked dominant. You feel really good when he comes into the game, and he feels really good as well. To me, when he's throwing the way he did, he's as good of a reliever as you're going to find."