Erik Goeddel is still on the 40-man roster and thus far this Spring he’s pitching pretty much as he did in Las Vegas last year – 4.50 ERA and batters hitting a robust .333 against him.
Cory Mazzoni has been a starter his whole career and been rather Gee-like in his execution. Thus far in Spring Training he's been flat out awful, though in very limited duty. He's never worked out of the pen before so there's no telling how his arm would respond.
So let's play a guessing game...if you are the Mets who would get the final two spots in the bullpen? There are two issues at play here -- who they should choose and who they will likely choose. My guess right now would be that Sean Gilmartin and Buddy Carlyle get the first crack at these spots since they stand to lose both of them if they don't come north with the team. However, based upon pitching Carlyle and Alvarez would probably make more sense as Alvarez has been able to strike out lefties and hasn't been too hittable. His control issues are almost Jack Leathersich level bad, but it seems out of character for Alvarez whereas it's been a chronic problem for Leathersich.