His right shoulder, the one that caused him to miss three games, seems to be 100 percent - or at least close to it.
But, like the rest of his team, Palmer still isn't satisfied.
The Cardinals are off to their best start in 40 years at 6-1, yet still see there's plenty of room for improvement if they want to keep the run going.
''We realize we can play better,'' Palmer said Wednesday. ''I think we're realistic in that we can play better and we need to play better.''
Palmer has yet to lose as Arizona's starting quarterback this season.
He led the Cardinals to a win over San Diego in their opener, sat out three games with a nerve issue in his shoulder - one of those a loss to Denver with Drew Stanton under center - and returned to win three straight games.
Palmer's numbers are impressive: 1,136 yards and eight touchdowns with an interception while completing 61 percent of his passes.
Against the Eagles last Sunday, he threw for 329 yards and a pair of touchdowns, including the 75-yarder to John Brown with 1:21 left that sent the Cardinals to a 24-20 win.
Still, it wasn't exactly perfect.
Palmer completed less than half his passes - 20 for 42 - and the offense stalled for a good chunk of the second half outside of the long pass to Brown and an 80-yard touchdown to Larry Fitzgerald early in the third quarter.
''Very average for him,'' was coach Bruce Arians' assessment of Palmer's performance.
Despite the win, Arizona's third straight, there was an air of negativity around the Cardinals' complex on Monday.
Arians was unhappy about mental errors, receivers running wrong routes, the inability to consistently run the ball and some missed opportunities to get sacks.
Regardless of what they've done wrong, the Cardinals are still leading the tough NFC West, are one of two teams left in the NFL with just one loss (with Denver) and in good position with tiebreakers with a 4-0 record against teams in their conference.
No matter how Arizona has done it, winning breeds confidence and the Cardinals can feel it building with each week.
''Realizing all the negative things that happened and we still keep getting wins, I do think we have a good swagger about us, a confidence, and that will continue to live if we keep winning,'' Palmer said.
Getting overconfident probably won't be a problem for the Cardinals.
Arians is there to make sure of it by pointing out all the mistakes they've made despite winning. There also are still plenty of players around from the 2012 team that lost 11 of its final 12 games after starting 5-1.
Besides, it's not like the schedule gets any easier from here.
Arizona plays at Dallas on Sunday and still has two games against Seattle, another against division rival San Francisco, along with games against Detroit and Kansas, both possibly playoff teams.
''We have enough veteran guys on this team to not hear all the applause, the slaps on the back, the press clippings and all that,'' Palmer said. ''There's a lot vets that have been on good teams that were out of the playoffs, had hot starts and finished terribly, or been good and never got to that great mark. So there's enough experience in this locker room that we'll hold each other accountable and take it one week at a time.''