IT's not unusual for a guy who can't hack it as a starter to become a decent reliever. Most of the great relievers were tried at starter at some point (I think even Rivera). Slate has been saying this for years about Corbin. If he could become an Ian Kennedy (decent reliever signed originally to a pricey starter contract), then he would be a contributor who could perhaps be traded with some money eaten. Really, the question is, is this guy who should be a reliever more of a contributor to this team as a terrible starter who you hope can eat some innings by becoming merely a bad starter?
I think the easy answer here is that when he starts, he costs the team games. If he's even a decent reliever, he wouldn't.
The problem is simply the backfill: is whatever sad sack goes to the rotation to replace him going to be even worse and cost the team more games? And the answer there is "probably not," especially if that sack is Espino. Sure, he's a 5 inning pitcher and not an especially good one, but his ERA over the last 3 seasons is more than a run lower than Corbin's.
The team was 6-25 in Corbin's starts last year. Outside his one decent month, they were 3-22. That's a performance that is team-killing. He would not kill the team as a reliever, nor would Espino as a starter: the team was 7-12 in his starts last year.
They won't do this, of course, but they should.
