I think you have to give Cole a serious look for a post-season spot ("I'll take 'things you never thought you'd ever say' for $400 please, Alex"). Ride the hot hand and all, and he's actually been pretty solid in his last few outings-- 13 hits and 4 ER in 14.1 innings for his last 3 outings-- and routine doesn't seem to much mess with his ability to pitch. I don't think he's the savior of the bullpen or our next ace, so don't get me wrong, but if I needed someone to eat some innings with very little notice, I'd have to give it some serious thought. Most of our guys can't go more than an inning or two, and some of them just suck if they're moved into an unfamiliar role (see 8th Inning Doolittle, 9th Inning Kintzler, or Bullpen Roark). Cole seems to be adaptable whether he's a starter or a long man or just goes an inning.
I am not sure you have to carry AJ Cole as a long guy. In regular season, yes, you need a long guy, but in the postseason even If you get beat up early you have to stay in the fight and try to fight back. Solis, Perez, and Grace all can go a couple innings in case of a Guthrie type disaster.
for the post-season, Perez has got to stick to lefties as much as possible. Even better if he can return to his niche of high leverage LOOGY. Righties are his undoing and I would not put Ollie out there for 2 innings of Cubs. Lefties are batting .227 against him, with .665 OPS; and righties are batting .283 with OPS of .888. Yikes.