The D'Backs are one of the best teams in the Majors against lefties and are one of the hottest teams in the Majors. Chico definitely hasn't pitched well at all lately but I'd keep him on the rotation for the rest of the season. He has earned that right since he is the only member of our starting rotation to make every start.
Keeping him in the rotation isn't helping him at this point. It's probably doing more harm than good, overall.
How can him, going out over and over again, pitching poorly be good for him?