Carson Palmer and Byron Leftwich have been friends since 2003, when they both were in the NFL draft and teams were trying to decide who deserved the nod as the better quarterback prospect.

"When you come out like that (as high picks) you do a lot of things together," Leftwich said.

That their careers would come to this – Palmer, still starting in the league not with the Bengals, who drafted him No. 1 overall, but with the Cardinals, and Leftwich as his quarterbacks coach – couldn't have been predicted. But it makes sense for both, even with Leftwich as a former draft peer.

For Leftwich, someone head coach Bruce Arians has long been priming for a potential coaching future, hindsight revealed he likely was headed here the whole time.

"I've been married to this (football) thing for a long time," Leftwich said with a chuckle. "Before I even knew what marriage was."

From the time Leftwich first played for Arians – the 2008 season in Pittsburgh, when Leftwich was the backup quarterback, Arians the offensive coordinator, and the Steelers beat the Cardinals for a Super Bowl win – Arians told Leftwich he thought like a coach.

Leftwich didn't want to coach after retiring following the 2012 season, wanting to get away from the game and see his family more than he had previously been able. It didn't stop Arians from annually asking. Last year, Arians tried again to see if Leftwich was interested in coming in as an intern.

"I was really struggling off the tee," Leftwich said with a smile, and agreed. In less than a week, "I was hooked."

When the team parted with running backs coach Stump Mitchell (who went to the Jets) after the season, Arians moved Freddie Kitchens from quarterbacks to running backs, and installed Leftwich with the quarterbacks. Arians called Kitchens' work with the running backs "fantastic" and likes that there is a different perspective for the backs, especially in the passing game.

As for Leftwich, "he'll be a head coach early and fast," Arians said.

Kitchens, at 42, isn't that much older than Palmer. But Leftwich is a true peer, having at No. 7 overall been drafted six slots behind Palmer.

"I've been around long enough to know I need it, I need coaching, tips and help and pointers," Palmer said. "I know when someone knows it and they don't and he knows it. I don't care if he's five years younger or 15 years older, he knows what he is talking about. And he played in the same exact system and he played for B.A., so there are a lot of positives with him."

Leftwich played under Arians for three seasons. His knowledge of the offense – like that of backup Drew Stanton – was excellent before even arriving in Tempe. While Leftwich was a starter in Jacksonville, his time behind Ben Roethlisberger in Pittsburgh gives him that secondary perspective.

"He had to feel his way a little bit, but he has as much experience as anyone in this building," Stanton said. "Being able to draw that out of him, but being able to talk with him, see what he sees and being able to have him as another resource … an extra set of eyes, especially for me, is invaluable."

Palmer said he thinks Arians would hire Stanton as a coach himself when Stanton's career ends, seeing similarities in both Stanton and Leftwich. Stanton isn't sure himself, given the grind that is NFL coaching, but then again, Leftwich wasn't sure once upon a time himself.

But Arians, it turns out, was right.

"I played the game as if I was a coach," Leftwich said. "I never really had the physical ability to run around. I could throw the ball, but I had to think my way through the whole time. I think (Arians) understood that and appreciated my knowledge, how much work I put into the game."