Raiders' Heyward-Bey leaves field on stretcher

Raiders wide receiver Darrius Heyward-Bey left the field on a stretcher Sunday after receiving a hit to his head.

During the fourth quarter, he caught the ball across the middle and was tackled. But as he fell to the ground, the back of his head hit the leg of Vikings linebacker E.J. Henderson.

Heyward-Bey's helmet popped off and he lay on the field, visibly in pain, before being placed on a backboard. Trainers examined him on the field for several minutes before a cart drove Heyward-Bey, strapped to the backboard, off the field.