5:30pm: Arnold will indeed not return this season, according to NFL Network’s Tom Pelisser o. The cornerback is set to undergo shoulder surgery that will end his season prematurely.
5:03pm: Terrion Arnold
is in line to miss further time in 2025. The second-year cornerback has been placed on injured reserve by the Lions, per Monday’s transactions wire. 
A shoulder injury has resulted in this move, one which will leave Arnold sidelined for at least four games. The Lions have five contests remaining in their regular season schedule. This news will deal another blow to the team’s secondary, a unit which has dealt with a slew of injuries over the course of the year.
Arnold has been limited to just eight games in 2025. The former first-rounder returned to action in time for Detroit’s Thanksgiving game after recovering from a concussion. Prior to that, Arnold dealt with a shoulder ailment which at one point threatened to cost him the remainder of the season. If he is to play again in 2025, another recovery process will need to be completed.
The Lions recently activated D.J. Reed and Khalil Dorsey from IR, giving them options at the cornerback spot. Shortly thereafter, veteran Arthur Maulet was waived . With Arnold now once again in store for an extended absence, it will be interesting to see if Maulet is brought back or if another move is explored. Detroit (7-5) sits 17th in the league in passing yards allowed per game.
Arnold served as a full-time starter during his rookie season, nothing 10 pass deflections along the way. The Alabama product has logged seven starts in 2025, but his snap share has dropped considerably (65% compared to 91% last year). Arnold has not developed as hoped in coverage, although his absence will still be felt as the Lions continue to deal with injuries in the secondary. The team will look to reach the playoffs with a strong finish to the season, and if that takes place Arnold could be available based on his recovery timeline.