I'm not sure you really need pitching prospects with Kelly's potential filtering through on a constant basis, especially right now for us, where we don't actually have room to play them. Unless we don't bring Beckett back there's just not a lot of places for people to play.
By the way, how does the trade equation change if we throw in Luis Exposito instead of Ryan Westmoreland? Last time I checked, the Padres didn't have much of a catcher. I mean, Hundley's OK, but he's replaceable, and we can deal with missing Expo probably better than we can deal with losing RWML or Casey Kelly.