Cardinals quarterback Drew Stanton fires a pass Sunday against the Rams in relief of an injured Carson Palmer.

Only two hours remained before kickoff back in 2014 when Drew Stanton was told he was going to start on the road against the Giants, after Carson Palmer realized his shoulder problems wouldn't let him play.

So really, it's not a big deal to Stanton that Palmer's status – and by extension, Stanton's – is up in the air for Thursday night's game on the road against the 49ers.

"Those of us in the locker room know how tough Carson Palmer is," Stanton said. "If he can find a way to play, he'll play."

Palmer remains in the NFL's concussion protocol, but coach Bruce Arians said he was more optimistic Monday that the

quarterback could be able to play in San Francisco than he had been post-game Sunday night. Palmer doesn't even have to practice, Arians said. The decision could come as late as when the team is taking off Wednesday for the trip, the coach added.

"Nothing surprises me with these guys getting healthy anymore," Arians said.

Arians said he talked to both Palmer and Palmer's wife, Shaelyn, Sunday night to check on the well-being of both. Stanton too said he thought Palmer was doing better.

Stanton called Palmer a "true professional," but is preparing – as usual – as if he himself will be behind center.

"That's why I am here, to fulfill these kinds of opportunities if they present themselves," Stanton said. "It remains to be seen."

In practice, Arians said Stanton was "outstanding -- for a walkthrough." Given the short week and the Cardinals practicing less than 24 hours after losing to the Rams, Arians emphasized the "walk" part of the walkthrough.

Stanton said on a short week, the prep is more mental than anything, and reiterated he knows he needs to improve on his

relief outing Sunday. Stanton was intercepted twice in 11 passes – once on a last-ditch Hail Mary – and had a third called back on replay.

He said he can't dwell on any rust he might have. Last season, Stanton only played seven games of mop-up duty for Palmer.

But in 2014, when Palmer first dealt with a shoulder injury and later a season-ending ACL tear, Stanton was needed. He came in after Palmer hurt his knee in a home game against the Rams and led the then-trailing Cardinals to a win, throwing a key touchdown bomb to John Brown.

Stanton's statistics were average – a 78.7 passer rating, a 55 percent completion percentage, seven touchdowns to five interceptions – but in his eight other appearances (all starts), the Cardinals went 5-3. More importantly, when Stanton himself was lost for the season with a knee injury, the Cards' playoff season limped to the end with a Wild Card loss in Carolina.

"You can draw on (that season) from the standpoint of, 'I feel good in how I prepared' and you trust in the process," Stanton said. "I think I felt good with what I was able to accomplish, but that means nothing going forward.

"The vast majority of these guys weren't even on the team. Each and every time you step on the football field, especially somebody in my position, you have to prove yourself."