Prater (left knee) was a non-participant at Thursday's practice, Zach Gershman of the Cardinals' official site reports.
Prater thus has just one more session to prove the health of his left knee this week before Arizona potentially makes a ruling on his status for Sunday's game in San Francisco. If Prater isn't able to perform his usual place-kicking duties this weekend, the team likely will elevate Chad Ryland from the practice squad, which will need to happen by Saturday's 4:00 p.m. ET deadline to do so.