It also depends on your position and the guy you're replacing. Since Reynolds is a good defensive first baseman, Overbay really has no value as a 1st base only replacement, especially considering his D is only "average" and he can't hit a lick. Bianchi probably has more value because of his positions, but you have to at least be able to outhit your pitching staff, or you are useless as a pinch-hitter. I'm not saying it's easy, just the easiest. Any player playing a position he doesn't usually play isn't easy. But you can plug in Lucroy or Maldonado at 1st for a day or 2 if it's needed. You probably won't get great defense, but you can get by. You certainly couldn't do that with them at SS or CF.