The quarterback moved to the Phoenix side following a trade with the Oakland Raiders earlier this year.
The head coach told reporters: "He fits in beautifully. He's a gym rat. He can still make all the throws. He's athletic enough to move around in the pocket. He's not one of those scrambling guys, never has been. I'm more of a traditional quarterback guy, anyways.
"He's fantastic. It's hard to go get a number one Draft choice like that at quarterback in the trade that we got. Like I said, he can still make every throw. He's as pretty a deep ball thrower as I've ever seen. He's still got it, and he's extremely accurate. A big thing is we've got to keep him upright.
"It took 24 hours and he had this football team in the palms of his hands. Defense got better because they now believe the offense can score points. I think it was an outstanding move for he and I."
The Cardinals play the St Louis Rams on Sunday.