Janssen had offseason surgery on his right shoulder before the season and the recovery took a lot longer than anyone expected. Every day seemed to bring a new challenge even though he would go on to record 34 saves in just 36 opportunities.
"It was a battle," Janssen admitted. "There were days when it felt great and then there were days when it felt terrible, and everywhere in between. There wasn't always a consistent reason for why I felt the way I did, but hopefully that's all in the past and I'm better for it this year. With a healthy season and a healthy offseason, once I ramp up to full speed, hopefully everything is in the past."
Janssen wasn't even expected to crack the Opening Day roster at the outset of last year's Spring Training because of the injury. He appeared in just two official Grapefruit League games but managed to get himself ready just in time to head north with the team.
Once there, he never looked back. The velocity was down but the numbers certainly weren't. Janssen relied on pinpoint command and a wide array of pitches to get through a season in which he posted an impressive 2.56 ERA while striking out 50 and allowing just 13 walks over the course of 52 2/3 innings.
The Blue Jays had to monitor his workload throughout the year, and there were a handful of days he wasn't available, but for the most part it was an overwhelming success. That's a credit to Janssen, because while a lot of other pitchers would have decided to shut it down, he found a way to gut it out.
The prolonged rest didn't come until the offseason and that turned out to be just what the doctor ordered. Just like any other pitcher, Janssen is in the process of working his arm into game shape, but he's finally feeling like his old self.
"I noticed it right away," Janssen said when asked how he felt after taking a break at the end of the year. "I was like, 'man, this doesn't hurt.' I was able to start my workouts at a normal time. I was able to lift the way I wanted to lift and prepare for the season the way I normally do.
"It was noticeable. I was struggling during the season to even do certain exercises in the weight room. It was just a battle, but one thing in this game is no one feels sorry for you. It was the hand I was dealt and I tried to get through it and I'm excited for this year with that being in the past."
There were some initial doubts about Janssen's ability to become a closer in the American League. He's not the prototypical hard-throwing reliever, but throughout the course of his seven years in the big leagues, that hasn't seemed to matter.
Janssen hasn't posted an ERA above 2.56 since 2010 and even then he finished the year strong with a 5-2 record and 3.67 ERA. Despite being the model of consistency, it wasn't until midway through the 2012 season that the Blue Jays finally decided to give him a shot at the ninth inning.
The end result has been just four blown saves in his past 56 opportunities. There are plenty of other relievers around baseball who get more attention, but that rate of efficiency ranks near the very top.
In many ways, Janssen always seems to be overlooked and that also could be said about how Toronto's bullpen entered the 2013 season. The Blue Jays relief corps was expected to be a weakness, but instead became the club's biggest strength.
"I think the front office and other people didn't necessarily know exactly what we had down there," Janssen said. "But we knew we had some talented guys and I think if this group of guys was in the United States and in a big baseball market they would get even more recognized than they have been.
"Obviously (Brett) Cecil and (Steve) Delabar got recognized for their great season by making the All-Star team, but Aaron Loup had a great season, Neil Wagner came in and had a great season. Sergio (Santos) when he was with us, was lights out. So I think we might have been sneaky at times but that's not because of the talent, it's because they're not as familiar names as they could be."
That won't be the case this season as the Blue Jays bullpen will now be expected to pick up right where it ended last year. There are plenty of question marks surrounding the starting rotation but the strength of this team will be preserving leads after the sixth inning.
Even if a couple of the familiar names falter, there's a long list of guys waiting to take their place. It's the most depth the Blue Jays have had in recent memory, and now it's up to the rest of the team to do its part if Toronto has any hope of becoming one of the surprise teams this season.
That's something Janssen thinks can happen even though the Blue Jays are coming off an extremely quiet offseason, with the signing of catcher Dioner Navarro being the only significant addition.
"We need a couple of guys in the rotation to step up and solidify the back-end of the rotation," Janssen said. "I think our offense is legit, I don't think there's a break in the offense. They're going to score runs, it's just whether we can prevent them from scoring as much as we are.
"The players didn't lose the expectations but we need to bounce back. We definitely won't have the record we did last year and if we had a do-over I think we'd win more games by just being more lucky. If it all clicks, everyone knows the type of talent we have and the type of roll we can go on."