Warren wasn't involved in the open portion of Wednesday's practice and appears likely to be listed as a non-participant on the Steelers' first Week 3 injury report, Brooke Pryor of ESPN.com reports.
Per Mike DeFabo of The Athletic, Warren was present for the session, but his lack of involvement with his healthy teammates indicates that he's either receiving a veteran's rest day or is tending to an unreported injury. More information on Warren's status will be known when the Steelers release their injury report shortly after practice concludes.