It appears Drew Stanton will be the Cardinals' starting quarterback this Sunday in Denver.
Carson Palmer reportedly suffered a setback in his recovery from a nerve condition in his throwing shoulder.
The 11th-year veteran missed practice on Wednesday to seek another opinion on the injury, which he suffered Week 1 against San Diego.
Bruce Arians hasn't yet ruled Palmer out, but says he's doubtful to practice on Thursday.
Stanton led Arizona to wins over the Giants and Niners, although the numbers suggest the victory over the G-Men was more in spite of him than a credit to his play (14/29 for 142 net passing yards).
The former Spartan threw two third-quarter TD passes to rally Arizona over San Francisco the next week.
For their part, the Broncos say they expect to face the same Cardinals offense no matter who's quarterbacking it.
Arizona is likely to get linebacker Alex Okafor and punter Dave Zastudil back from injuries that have prevented them from playing in 2014.
Another boost to their linebacking corps came Wednesday, as Desmond Bishop was re-signed after having been among the team's final cuts.
Danny Trevathan (leg) was again a full practice participant for Denver on Wednesday, while Louis Vasquez (ribs) and Lerentee McCray (knee) were limited. David Bruton (ankle) was again held out.
Virgil Green confirmed that he'd passed the league's concussion protocol, and was a full participant on Wednesday.