I think the Orioles should not have ANYONE in the closer role.
I would much rather see Showalter treat the 9th inning the same as if it is the 8th inning, which is to say ... send someone out there to pitch the ball and get 'em out. I do not like the closer role and I think unless you get a special guy who thrives on pressure long-term (e.g. Rivera, Eckersley, etc.), you're better off without a defined closer.
I think that if possible, let whoever pitched the 8th also pitch the 9th. If that's not desirable, then get whoever would be the best matchup against the upcoming batters warmed up for the 9th and have that person pitch.
IMO, a pitcher who is given the closer role has a lot of unwarranted pressure put on them (as in YOU MUST ALWAYS BE PERFECT). Some pitchers thrive on that long-term (Eckersley, Rivera, etc.). Others may do well for a while but then the pressure builds up and they can't handle it.
Could Hunter close? Maybe, for a while. Could Matusz? Maybe, for a while. Why take the chance that they become a decent closer for a year and then the pressure overwhelms them and they turn into another JJ?
Take the pressure off of everyone by not emphasizing the role. Everyone pitches and tries to get people out, regardless of the inning. End of story.