My offense is so bad right now I don't even think I could afford to trade Nevin, much less Lance Berkman. I'm getting zero power from everybody else. Honestly, if I were you, I'd be patient at 1B and pile up the saves while Baez is still closing, Jenks isn't imploding, and Papelbon hasn't been moved into the starting rotation. They've been great for you so far, and should continue to be for at least a little while longer.