And those off days BK wants for Casty so badly would just put Rojas (or worse, Wilson) in the line-up against a RHP (since Kepler and Marsh would already be playing). There might be some days when the defense would provide a marginal upgrade, but just as many where Casty would get that one big hit.
The funny thing is if Schwarber was the LF and Casty was the DH I don't think there would be anything to whine about. Schwarbs would just be the same terrible big hitting LF the Phillies historically have (and he's probably not a better fielder than Casty at this point). Casty would have the 11th-highest OPS of MLB DHs (though he's also 12th among RFs). And Marsh may well be a Top 5 - but definitely Top 10 - offensive CF assuming he gets back to his normal level (.750 OPS would make him 10th).
Major league outfielders are not as good as people think, if you don't have a clear All-Star, and there aren't many of those. Which is why Marsh and Castellanos were both among the Top 6 vote-getters for OFs last year.
