The Cardinals released Riley on Tuesday, Darren Urban of the team's official site reports.
Riley started this past Sunday's loss to the Panthers and played 79 percent of defensive snaps, recording six tackles. This move signals that Jalen Thompson (ankle) could return from IR soon, and perhaps Chris Banjo (hamstring) and Budda Baker (thumb) are nearing returns as well. If Riley clears waivers, he could land on the Cardinals' practice squad.