If you look at last year’s playoff teams, the majority of them shared one important strength: a strong bullpen.

Red Sox GM Ben Cherington clearly had this in mind when he assembled this year’s roster. Despite already having an established closer in Andrew Bailey, he went out and got another one in Joel Hanrahan. He signed Koji Uehara, who was impressive as a setup man in Texas. These arms were added to a pen that also features Junichi Tazawa (dominant the second half of last year), Daniel Bard (a top-five reliever in 2010-2011), Craig Breslow, Andrew Miller and Franklin Morales.

Cherington has constructed a bullpen that will have numerous guys who have all been either closers or elite setup men in the recent past. He’s also strengthened the bottom of the bullpen rather than maximizing the quality at the top.

Ultimately, what you have is a pen that could, if all goes right (the same that could be said about the starting rotation), make the Sox one of the toughest teams in the majors to score on from the sixth inning on.

John Farrell now has endless matchup possibilities, with a bullpen full of power arms capable of getting swings-and-misses in key situations.

And yet, because relief pitchers are so inconsistent from year to year, a few unfortunate events and we could be scrambling for arms by late summer.

Here’s how things set up going into the year:

Joel Hanrahan: Anointed closer the minute we traded for him this winter. Inconsistent so far in spring training.
Andrew Bailey: Injuries have derailed his Sox career thus far. All-star closer in Oakland. How will he respond to his new role as the 8th inning setup man?
Koji Uehara: Over the past three seasons, the 37-year-old right-hander has a 2.36 ERA, 183 strikeouts and only 17 walks in 145 innings for the Orioles and Rangers.
Junichi Tazawa: The best relief pitcher last year for the Sox. Has the potential to close.
Daniel Bard: Looks like he has returned to form this spring with John Farrell back in the mix. Velocity is back. Were injuries a factor last year? Can he remain consistent?
Craig Breslow: Injured to start the year. Effective left-hander with a long proven track record of success.
Andrew Miller: The former #6 overall pick  resurrected his career last year as a left-handed specialist.
Franklin Morales: Long reliever who could return to the starting rotation if there’s an injury or one of the starters is ineffective.

On the bubble:
Alfredo Aceves: Really impressive two years ago as a long reliever/spot starter. Less so as a closer in 2012. The biggest question is his attitude.
Clay Mortensen: Out of minor league options. Effective last year in limited opportunities.  Hard to see the Red Sox waiving him outright.

How do you see the Red Sox bullpen turning out? Will Hanrahan be closer all year? Is a trade coming?