It's funny...I posed that question to Patrick last week about having him in the pen. When a guy only has to worry about 1 inning they tend to eliminate the walking issues since you don't have a full game plan on setting up guys for later innings. 

I have always felt Chatwood was better suited for the pen due to his smallish stature and having the Tommy John...For a career longevity move, its where he should be. When his stuff is right...he could be a dominant closer..Sort of reminds me of a Huston Street type if he embraces that role.