There's been talk for, well, ever, that Castillo's non-throwing arm defense is poor. Considering Theo kept Varitek WAY longer than the numbers say he should have, you have to think this front office probably values those things. I think with Castillo's big callup, and the poor state of catching around the league, he gets moved somewhere. Not to mention, if the Cubs' internal numbers jive with ZiPS, then Clevenger's not a huge dropoff from Castillo on offense. ZiPS has Castillo at .240/.309/.398 and Clevenger at .261/.309/.361.