Simply tell him that you want to expand the roster beyond the 25 man restriction. He gets Major League money and Major League service time towards his pension and some ABs on a rehab in Louisville with a chance when a real injury happens down the road. If the alternative is DFA and the hope that some team that just cut down finds room for a 28 year old who has never been able to stick in the majors, I'm pretty sure he won't mind saying his side hurts or that he twisted his back during ST.