TORONTO -- The Blue Jays' bullpen in 2016 was a Jekyll and Hyde situation. Nothing seemed to go right in the first half, but after the All-Star break, the relievers became as reliable as it gets. Which version will show up this year is anybody's guess.
Toronto's chances at contending could very well come down to the performance of its late-inning relievers. This is a team that will have to win from the mound, and while there are very few questions about the rotation, the same cannot be said about the bullpen.
Brett Cecil and the surprisingly efficient Joaquin Benoit left via free agency, and the Blue Jays have yet to sign a reliever to a Major League deal to fill either void. Unless another piece or two is added, some trial and error should be expected from manager John Gibbons as he gets a feel for this group.
Around the Horn: Starting rotation
In the latest edition of MLB.com's Around the Horn series, we take a closer look at Toronto's bullpen:
Roberto Osuna 
Osuna hasn't even turned 22 years old yet, but he seems like a seasoned veteran. He's fresh off two successful seasons as Toronto's closer, and there's no reason to doubt Osuna will be able to make it three in a row. He's one of the top relievers in the game, and after picking up 36 saves last season, a similar performance in 2017 should be expected. The only question here is whether the heavy workload will eventually take a toll, especially considering he's coming off a year in which he threw 83 innings between the regular season and postseason. Gibbons will have to resist going to Osuna too much, but that will be easier said than done based on need.

Jason Grilli
Grilli, in a lot of ways, was responsible for saving Toronto's 2016 season. The bullpen was a total disaster when he arrived in late May, but he quickly became a trusted arm of Gibbons and joined forces with Osuna, Joe Biagini and an improved Cecil to help turn things around. Grilli posted a 3.64 ERA over 42 innings for the Blue Jays, and they would happily take those kind of numbers again. The big question is, at 40, if Grilli still has enough left in the tank to prove that he can be a reliable setup man.

Biagini
There was a time when the Blue Jays were openly considering moving Biagini into the rotation this year. That likely won't happen now; the decision is based on necessity more than anything else. Toronto has its five starters, but there are plenty of openings in the bullpen and a clear need for someone like Biagini. He showed he was up to the task with a 3.06 ERA over 67 2/3 innings in his first MLB season, but relievers can be very unpredictable from one year to the next. The Blue Jays will want more of the same from him in 2017, but expecting it seems like a risky proposition.

Aaron Loup
The biggest area for concern in this bullpen is the lack of a bona fide lefty reliever. Loup used to be one of those guys, but he is coming off a pair of disappointing seasons, and he'll really need to show things have changed before expectations can be raised. With Cecil gone, Loup has the most big league experience of the potential replacements, but he will also receive competition from Matt Dermody, Chad Girodo and Brett Oberholtzer. More additions likely will have to be made here, but until that happens, Loup is the early favorite for a setup role. The walks will have to come down if he's going to cement that position, because a the 5.02 ERA he posted in 2016 simply won't cut it in this role.
Gavin Floyd
The Blue Jays decided to bring back Floyd on a Minor League deal with an invitation to Spring Training. If healthy -- and that's always the big question mark with Floyd -- he is expected to make the team as a middle reliever. Floyd enjoyed some success in that role last season, but he also experienced difficulty bouncing back from appearances and struggled when working on back-to-back days. The talent is there, and the high-upside Floyd will be given every opportunity, but there will be plenty of skeptics along the way.

Mike Bolsinger
Bolsinger is the early favorite to win the job as the Blue Jays' long reliever. One thing helping his cause: Bolsinger is out of options and cannot be sent to the Minors without clearing waivers. Instead of losing him, Bolsinger figures to make the team with a decent Spring Training and also serve as a potential spot starter if anybody gets hurt. Bolsinger was acquired from the Dodgers in a deal for reliever Jesse Chavez and has a 4.61 ERA over 189 1/3 career innings. Almost all of his experience has come out of the rotation, but the bullpen is likely in his future in Toronto.
Glenn Sparkman
Hey, the Rule 5 Draft worked out so well for the Blue Jays last year, why not try it again? Biagini was the lucky winner before, and now Toronto is hoping Sparkman will produce similar results. Sparkman returned from Tommy John surgery last year, which is likely one of the reasons he was available in the Draft, but he is back to full strength and will be looking to transition from the rotation to the bullpen. He throws mid-90s with a slider as his best pitch, but the 24-year-old will need a strong camp to make the team.
Danny Barnes
Barnes has the potential to become the breakout reliever on this list. He got a taste of the big leagues last season and performed well, with a 3.95 ERA and 14 strikeouts over 13 2/3 innings. A big debate in Spring Training will be whether the Blue Jays are best served giving jobs to the out-of-options pitchers and relievers on Minor League deals over someone like Barnes. Toronto could preserve its depth by optioning Barnes to the Minors, but if he really is that good in Spring Training, the team may have no choice but to put him on the roster.

Other names to consider
Dennis Tepera will have a chance to compete for a job in Spring Training, and no matter what happens, he's likely to make some appearances at the big league level in 2017. Odds are it will be the up-and-down role from Triple-A Buffalo that he experienced each of the past two years ... Wil Browning, TJ House and Chris Smith will be among the other relievers to keep an eye on.