It was back to business as normal during a series opener against Cleveland, though, as Janssen allowed just a bloop single in an otherwise clean inning to preserve a 5-4 victory and record his first save of the year.
"When he started closing a couple of years ago, he's been almost perfect," Blue Jays manager John Gibbons said after the win. "He was kind of forced into that role a couple of years ago when Santos went down and he's run with it. I mean, he's reliable.
"Early on in the season, we started out pretty good coming out of the 'pen closing some games, and then we hit a rough spot. So it's definitely good to have him back. You kind of just eliminate that inning, thinking he's got the ninth."
Janssen, who missed the first five weeks with a strained oblique, made his season debut on Monday night with a scoreless inning against the Angels. He allowed a leadoff walk, but was then able to come back and retire the next three batters he faced. Perhaps the most positive aspect of that outing was that Janssen arrived at the ballpark less than 24 hours later feeling fine and ready to pitch on back-to-back days.
That's especially encouraging considering Janssen's injury ended up taking a lot longer to heal than originally anticipated. That's not uncommon with strained obliques, as the soreness often has a tendency to linger and it's a difficult injury to receive effective treatment.
The 32-year-old attempted to begin a rehab during the middle of April, but had to be shut down because of the continued discomfort. He eventually returned and made three appearances with Double-A New Hampshire before he was activated from the 15-day DL.
"I think it can always get better," Janssen said after his debut. "I hate walking anybody, let alone the leadoff guy, but hopefully that was just a nerves thing and I'll get back to my game, which is attacking hitters and throwing strikes."
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.