I'm not sure why postseason concerns are silly.
He was an absolute force in his rookie year (8 years ago)and he was good in his one 2014 game with the Tigers.
Other than that he been pedestrian, and that's being kind.
If the rest of the rotation can pitch well, the Sox can probably get away with an average pitcher in there, but it wont be easy.
A 6.70 ERA in last year's playoffs isn't the least bit funny.