Mills is a familiar face brought back specifically because Detroit's safety room has been hit hard by injuries; he played three games for the Lions down the stretch last season after being claimed off waivers and knows the system. At 32, he is pure insurance depth rather than a building block, but his resume of 92 career starts makes him a credible fill-in.
Strengths: Extensive veteran experience with 92 career starts and recent, direct familiarity with Detroit's defensive scheme.
Weaknesses: At 32 and on the practice squad to start the year, his role is strictly as emergency depth behind the regular safeties.