Walker dealing with herniated disk in back surgery an option (Yahoo Sports)

Second baseman Neil Walker was out of the New York Mets' lineup for a fourth straight day and the team revealed he has a herniated disk in his back. Both Walker and the Mets had previously classified the injury as a stiff back. Manager Terry Collins indicated he wasn't at liberty to reveal the exact diagnosis during Tuesday's pre-game news conference, but general manager Sandy Alderson shared the condition to a few reporters early Wednesday afternoon.