Knight (concussion) officially didn't practice Thursday, Darren Urban of the Cardinals' official site reports.
Since exiting Week 8 action with a concussion, Knight hasn't been able to log any practice reps, which generally isn't a good sign that he'll be available Sunday at Seattle. Arizona may make a ruling on Knight's status once it posts Friday's injury report, and if he's indeed sidelined for that contest, Tyler Allgeier stands to serve as the team's workhorse running back this weekend, with Evan Hull likely backing him up.