The Lions placed cornerback Terrion Arnold on injured reserve Monday, according to the NFL’s transactions wire.
He did not practice on Monday with a shoulder injury.
Arnold missed two games earlier in the season with a shoulder injury that initially appeared season-threatening. It’s unclear whether his current injury is to the same shoulder.
He will have to miss four games, with the regular-season finale the earliest he can return.
In eight games, Arnold has an interception, eight pass breakups and 31 tackles.
The Lions now have D.J. Reed, Amik Robertson, and Rock Ya-Sin as their top three cornerbacks.
In a corresponding move, the Lions claimed tight end Hayden Rucci off waivers from the Dolphins in a corresponding move.
The team also placed center Frank Ragnow on the retired list after he failed his physical.
The Lions designated tight end Shane Zylstra to return from injured reserve, opening his 21-day window.
They signed wide receiver Andrew Armstrong, tight end Giovanni Ricci and running back Jabari Small to the practice squad. They released defensive back Tre Flowers and offensive guard Netane Muti from their practice squad.
