Do not drop Fuentes. He is sick despite pitching in Coors. This is tough for me to say, because I'm a die hard A's fan, and Duch is my boy, but I wouldn't drop anyone on your roster for him. He's probably not in danger of getting picked up, so what I would do is try to trade two of your players away for one better player and use the newly opened roster spot for Duch if you feel very strongly about picking him up.
My team: http://www.fantasybaseballcafe.com/forums/viewtopic.php?p=2139669#2139669