this may be a dumb thought, but maybe they are actually only thinking about giving butler one (maybe two?) starts at the MLB level to just see how he fares. If he's completely lights out awesome then, yeah, keep him there. but if he's merely pretty good (or obviously worse) then you turn to Monty. I'm basically with TT (because, as a rule of thumb that's always the smart money move) but I could see them maybe wanted to just get a glimpse of how he handles himself back in the big show and then re-evaluate and possibly send him back down.