Arians, calling Palmer a game-time decision, said Friday he will will wait for pregame warm-ups to make a final decision about his quarterback. But he's confident that Palmer, who is listed as questionable after being limited in practice, will be ready to go.
"I've got to watch him warm up and throw and see how he is," Arians said. "I got all the confidence in the world he ain't missing (the game)."
Palmer hurt his right elbow on the Cardinals' third play of the game last Sunday against the Eagles when he was sacked Trent Cole. Palmer was seen wincing in pain during the play, then jogged off with his right arm cocked at 90 degrees at the side of his body.
Arians said he can't measure the importance of having the regular quarterback in the lineup, although by looking at teams around the league such as Green Bay, the significance of having Palmer is unmistakable.
If Palmer can't play, the offense will be in the hands of backup quarterback Drew Stanton, who hasn't thrown a regular-season pass since Week 14 of the 2010 season.
"I got all the confidence in the world in Drew in knowing what to do and everything, but it's still different for the other guys around them," Arians said. "If it comes to that, we'll deal with it and Drew will do a hell of a job."
Stanton was not made available Friday for comment.
Besides running back Rashard Mendenhall, who played under Arians in Pittsburgh, Stanton has the most intimate knowledge of the Cardinals' scheme because of the season he spent with Arians in Indianapolis.
"Having been with him all last year there was never a doubt when he played in the preseason he was spot in, and in practice, all week you would've thought he was the starter because he was spot on, ball was out, even a little quicker than sometimes receivers weren't ready for it because he does know the offense inside and out," Arians said.
Arians won't adjust the offense if Palmer does play to compensate for his elbow. Arians also isn't concerned that Palmer didn't have the usual number of reps with the first team because the Rams don't run a complicated defense.
"He's so in-tune to the offense now and all the guys are, that sometimes it's good at this time of the year to give the veteran a couple days off and let the young guy get some reps, anyway," Arians said. "I have no problem. He got (the) mental reps that he needed to, and I'm sure he's going to be fine throwing the ball."