Well, I think it stands to reason that if they're moving Johnson, then the Rangers are sending more back. Grabner, Nash, or possibly even Zucc. I made sort of a joke post a few weeks ago about Tampa being able to fit Zucc and McD with 50% retained on both simply by moving Johnson out.
I have no doubt Tampa could include enough pieces to entice the Rangers in a deal like that, but the problem is it's such a huge trade that it's almost impossible to pull off. There's something to be said about Zucc and McD having familiarity with Callahan and Girardi, but to disrupt the team that much this late in the season seems irrational.