Rethinking Jacoby Ellsbury in left field

Earlier today I heard a bit of an interview with Peter Gammons on WEEI and he discussed some interesting topics, but the one that really caught my attention was the discussion on Jacoby Ellsbury. Gammons believed the Red Sox should and are contemplating a move for Ellsbury to left field. I have done some research into this before, but there was a new argument for doing this. Gammons believes that stealing 70 bases is beating up Ellsbury and making him less effective defensively. His reasoning is a comment he attributed to Rickey Henderson that I have been unable to locate. Henderson claims that his extensive number of steals was beating up his body and effecting his ability to man center field.