Detroit's Mathis leaves with head injury
The 6-foot-1 Mathis, who signed with Detroit before this season after 10 years with Jacksonville, went down in the first quarter. He was able to walk off the field but was evaluated for a while on the sideline. He eventually started walking around with a helmet in his hand, but the plan was to evaluate him again at halftime.
During the second half, his status was downgraded, and he will not return.
Without Mathis, the Lions needed to rely more on rookie defensive back Darius Slay.
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