I would rather have him build up his strength. I agree that it's better that he struggles now in a lost season, than when it really matters. This isn't the same case with Strasburg, Sale did not have TJ surgery.
That said, I don't understand why he was out there for the 7th inning last night. We don't need to see him throwing 110+ pitches per game. If he needs to skip a start, that is acceptable.