Fantasy baseball: Granderson for Papelbon and a starting pitcher?

Matsui for Jenks isn't going to work out. He wants Matt Cain for Jenks, and I can't give up any starting pitching. He's willing to trade Jonathan Papelbon and someone else for Curtis Granderson, and I pretty badly need better starting pitching. His starters are Jake Peavy (yeah right), Dustin McGowan, Johnny Cueto, Edinson Volquez, Cliff Lee, Brett Myers, Phil Hughes, Jeremy Bonderman, and Jon Lester. Or do I keep Granderson? I drafted Manny Corpas, and losing Granderson would hurt but replacing Corpas with Papelbon would make it hurt a lot less.