That's a tough question to answer, because the Sox are not looking to pick up a 4/5 starter one year away from free agency. There are teams out there for whom Gavin would be a substantial upgrade to their rotation. By himself, he gets you a very good bench/platoon bat, a decent reliever, or a promising prospect. Find a team that also has a need for Thornton and Quintana and then you're talking about an impact player in return.