Billings (knee) is listed as questionable for Sunday's game against Seattle, Tyler Drake of ArizonaSports.com reports.
Billings popped up on Thursday's injury report due to a knee injury, suggesting that he tweaked his knee during Wednesday's session. His status for Sunday's NFC West tilt may not be officially known until 90 minutes before the 4:25 p.m. kickoff, when the Cardinals announce their list of inactive players. Roy Lopez is working through a groin injury, so the Cardinals enter the weekend with Walter Nolen and L.J. Collier as the only healthy defensive tackles on the active roster, though defensive ends Darius Robinson and Jordan Burch could also operate in the interior if need be.