Due to ongoing headaches from his concussion (in which he did not impact his head, but did continue to play after a "whiplash" incident).
Another lost year for the Mets. I wonder if Bay can rebound from his lost '10 as he did from his lost '07. Obviously he's older, but a lot of people looked awfully foolish dismissing Bay in the winter of '07/'08. A fresh start in '11 should do him some good.