The Detroit Lions thought they were trading from a position of strength when they dealt Quandre Diggs to the Seattle Seahawks last week, but just like that they are short-handed at the safety position.
Tracy Walker suffered a potentially serious knee injury in the second half of Sunday's 31-26 win over the New York Giants.
Walker was injured with 4:54 to play in the third quarter when he collided with Christian Jones while trying to shake loose of a Giants receiver on a pick route.