Head coach Mike LaFleur revealed Monday that Knight is in the concussion protocol following Sunday's overtime win in Dallas, Josh Weinfuss of ESPN.com reports.
Knight took a shoulder to the helmet from a Cowboys defender in the third quarter of Sunday's game, and after a visit to the locker room, he was ruled out with a concussion. It marked the second Cardinals RB to exit and not return in Week 8 -- Jeremiyah Love suffered a "new" ankle injury, per LaFleur -- so at the moment Tyler Allgeier is the top healthiest member of the team's backfield.