Williams (knee) was ruled out for Thursday's contest against the Saints, Darren Urban of the Cardinals' official site reports.
Williams will miss a second game in a row due to a knee injury, but James Conner (ribs) may be able to avoid that fate, according to head coach Kliff Kingsbury, who told Tyler Drake of ArizonaSports.com on Wednesday that the second back is a game-time decision. Whether or not an active Conner would lead the backfield remains to be seen, but if he's limited or out Thursday, Eno Benjamin (foot) is line to handle much of the backfield reps after ending Week 7 prep with a full practice.