We explored this possibility a few months ago and don't like it. Pedro was topping out at 86MPH in Game 6 of the World Series last year with normal rest, after only a few months of pitching. What is to make us think he will be any more reliable being a year older?
If I told you the Phillies would let go of both of their starters from Games 1 and 2 of the Series this off-season, and then only bring one of them back, would you want/expect it to be Pedro? THIS is the reason why you don't trade Lee for B-level prospects.