I'll put it this way.
If Eddie Guardado becomes a Red Sock in the next few weeks, Foulke is a set-up man.
If they don't deal for a closer, Kieth will get the job back when he returns.
If Kieth sucks in that opportunity, Timlin will take over.
Schilling will not remain in the bullpen all year, IMO. They will either deal for another closer and not even give Foulke a chance, or give it to him, and hope he does well, otherwise give it to Timlin or Arroyo.