Terrible news for the Marlins and Willingham owners (myself included -- he is on my one team that is doing well and he was instrumental in my hot start).
Looks like a herniated disc that could even require surgery.
He isn't resuming baseball activities for at least ten more days.
If you have room for him (I do), keep him (I am). Otherwise, if you want a dead spot on your roster through the all-star break, it looks like Willingham's your man.