Toronto's right-handed reliever has been one of the most valuable components on the Blue Jays this season. He stepped into the closer's role in early May and has been relatively flawless ever since.
In a year that has been marred by injuries, Janssen's presence at the back end of the bullpen has been the one constant for manager John Farrell and the rest of the Blue Jays roster.
"He's stabilized it," Farrell said of Janssen's effect on the bullpen. "He comes to the mound in the ninth inning, and I'm not going to say you're ever relaxed, but you feel pretty darn good with him coming to the mound.
"He throws strikes, he controls the running game, he pitches with a lot of energy. He has great mound presence, he can attack lefties. He has stepped into that role without trying to be someone else, he has been the same consistent pitcher, and we're thankful to build back to that at the end of the game."
Since taking over the closer's role on May 9, Janssen has gone a perfect 13-for-13 in save opportunities. He has allowed just six baserunners during those 13 2/3 innings of work, and in nine of the outings Janssen has faced the minimum number of batters.
The streak of 13 consecutive saves is currently the fifth-longest in the Major Leagues and the most for Toronto since Billy Koch notched 21 straight during the 2000 season.
It isn't the number of saves that have been most impressive, but how easily they've been recorded. It's a far cry from the 2011 season, when the Blue Jays tied for the American League lead in blown saves with 25 while using an ineffective trio of Frank Francisco, Jon Rauch and Octavio Dotel.
A similar fate could have occurred this year following an early-season injury to right-hander Sergio Santos and the prolonged struggles of Francisco Cordero, but Janssen has found a way to right the ship.
"It has been our season," Blue Jays catcher J.P. Arencibia said. "I think a lot of the success we've had is thanks to him. I'm glad they finally gave him the opportunity to do it, because I think just knowing his personality, knowing his makeup and stuff, he's a guy that's going to succeed in that role.
"It's not easy to get the last three outs of the game. I think his intensity, what he can throw, the amount of pitches he can throw for strikes on both sides of the plate, makes it hard for any hitter."
Janssen has been getting far more attention this year because of his ninth-inning role, but the fact is that he has been one of the Blue Jays' most reliable pitchers for a number of years.
The California native transitioned from starter to reliever in 2007 and promptly became an elite setup man. He posted a 2.35 ERA in 72 2/3 innings for -- then -- manager John Gibbons before experiencing shoulder problems the following spring.
That caused him to miss the entire 2008 campaign, and when he came back in 2009 he still wasn't in top form. It wasn't until the following year when Janssen was back to full strength, and ever since he has been a known -- albeit at times underutilized -- commodity.
Janssen posted a 3.67 ERA in 2010, but despite a strong track record he got caught up in a numbers game and had to spend part of April 2011 in the Minors. He rebounded nicely with a 2.26 ERA in 55 2/3 innings, but it wasn't until this year that he has found himself in a defined role.
"I feel like in years past I was pitching anywhere from the sixth to the ninth inning," said Janssen, who was taken by Toronto in the fourth round of the 2004 First-Year Player Draft. "Winning games, losing games, so you're always on high alert. At times the phone would ring and you'd wonder if it was you every single time. Now having a rhythm with John [Farrell], he's made that easier, and then with a more defined role you don't get surprised as often."
Janssen now knows exactly what to expect, but the season didn't necessarily begin the same way. He teamed up with lefty Darren Oliver and right-hander Jason Frasor to form a reliable middle-relief trio, but the eighth and ninth innings were left to Santos and Cordero.
It wasn't until Santos went down with a season-ending shoulder injury and Cordero blew three consecutive saves in May that Janssen received the opportunity for which he had been waiting a long time.
The closer's job comes with a lot of added pressure, but in many ways it's an easier role, because for perhaps the first time since 2007, he knows exactly when he'll be used and has ample time to prepare for each scenario.
"I've kind of enjoyed knowing my situation and getting ready for it," said Janssen, who is under contract through 2014. "In the seventh inning, you start preparing for where you think that slot's going to be, and if you need a refresher on a guy or two, you can have a conversation with some of the guys down there or get it in our scouting report binder and go about it that way.
"But it has just been nice to be able to focus all my energy on a situation and just use everything I have for that time, and then get out of there and hope that you can do it again tomorrow."