Terrion Arnold: Everything you need to know

Arnold (shoulder) was placed on injured reserve Monday, Eric Woodyard of ESPN.com reports. Arnold made his return to action in the team's 34-27 loss to the Packers on Thanksgiving after missing two games while recovering from a concussion. The cornerback recorded four solo tackles in the contest, but he may have suffered a shoulder injury in the process. Arnold missed a pair of contests in October with a shoulder injury, and it's unclear if he aggravated that issue or if he suffered a new injury. The 22-year-old popped up as a non-participant at the team's practice session Monday, and he's now set to undergo shoulder surgery this week, which will sideline him for the rest of the regular season, per Tom Pelissero of NFL Network.

Arnold recorded four solo tackles in Thursday's 31-24 loss the Packers. The cornerback returned for the first time since Week 10 after working through a concussion and played 17 defensive snaps, while backup Rock Ya-Sin saw nine. D.J. Reed and Amik Robertson led Detroit's cornerback room in snaps for the game, with 54 and 59, respectively. Now that Arnold is back, though, he should continue to play a role, as he has eight pass breakups on the year.

Arnold (concussion) is active for Thursday's Week 13 tilt against the Packers. Arnold suffered a concussion in Week 10 against Washington and missed Detroit's subsequent two games. The second-year cornerback has since cleared the NFL's concussion protocol and will return to action Thursday. Arnold should return to his starting slot, thus sending Rock Ya-Sin back into a rotational role.