Lions cornerback Rashean Mathis has left Sunday's game against the Chicago Bears because of a possible 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 being 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.
Without Mathis, the Lions needed to rely more on rookie defensive back Darius Slay.
AP NFL website: www.pro32.ap.org