Howell, 33, is an 11-year veteran who spent six seasons with the Rays (2006 to 2012) and is coming off four years with the Dodgers. He has a career 3.77 ERA over 608 2/3 innings and went 1-1 with a 4.09 ERA last season in Los Angeles.
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He takes the spot of Brett Cecil, who signed a four-year deal with the Cardinals earlier in the offseason. Toronto had lefties Aaron Loup, Matt Dermody, Brett Oberholtzer and Chad Girodo, among others, competing for a job in the bullpen but was lacking a proven veteran.
Howell struggled at times in 2016, with 44 strikeouts and 15 walks over 50 2/3 innings, but he posted an ERA of 2.39 or below from 2013 to 2015. One of the reasons for the down year was a reverse split, with lefties hitting .302/.343/.417 compared with .262/.333/.369 for righties. That went against a career track record of a .624 opponents' OPS for left-handed hitters vs. .728 for righties.
Toronto will be hoping for a bounceback year that is more in line with Howell's career numbers; he will likely join Roberto Osuna, Jason Grilli and Joe Biagini as the club's late-inning relievers. Osuna is set to return for his third season as the Blue Jays' closer while Howell, Grilli and Biagini figure to pitch a lot of high-leverage innings in middle relief.
Beyond those four, the Blue Jays will have three jobs up for grabs this spring. Gavin Floyd should be able to secure a job with a strong camp, and right-hander Mike Bolsinger is the early favorite for long relief. That would theoretically leave one job available for a group that includes Rule V pick Glenn Sparkman, Danny Barnes, Ryan Tepera, the lefties and perhaps a surprise candidate or two in Spring Training.
The Blue Jays' roster does seem relatively set, but the club could still search for improvement in left field and in the bullpen. Ezequiel Carrera and Melvin Upton Jr. form a potential platoon in left, with Dalton Pompey as the wild card to watch in Spring Training. An upgrade at the position hasn't been ruled out, and adding a reliable reliever will almost always be a priority.
Gregor Chisholm has covered the Blue Jays for MLB.com since 2011. Follow him on Twitter @gregorMLB and Facebook, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.