Montgomery (thigh) isn't practicing Wednesday, Colton Pouncy of The Athletic reports.
Montgomery said Sunday he might need "a couple weeks" to recover from his thigh bruise, while head coach Dan Campbell used the term "day-to-day" to describe the running back less than 24 hours later. Either way, Montgomery was never expected to practice Wednesday, and his potential absence Sunday against Atlanta positions rookie Jahmyr Gibbs to serve as Detroit's top back while Craig Reynolds and Zonovan Knight serve as depth option. Gibbs will most likely dominate the snaps if Montgomery sits out Sunday, with Reynolds likely subbing in for some carries and perhaps a target or two.