Lions rookie Terrion Arnold told reporters that he feels like Detroit’s secondary is “the best secondary in the NFL.”

Detroit added rookie cornerback Terrion Arnold to Thursday’s practice report with a groin injury. He was limited in the day’s session. Arnold, the No. 24 overall pick of this year’s draft, has recorded six passes defensed and a fumble recovery this season. He’s started all 10 games and been on the field for 91 percent of Detroit’s defensive snaps.