TEMPE, Ariz. -- With just days left before the Arizona Cardinals unveil their secretive offense against the Detroit Lions on Sunday, first-year coach Kliff Kingsbury still can't get a read on how his star quarterback, No. 1 pick Kyler Murray, is handling the moment.

No one can.

Murray is quiet by nature, and has been since he was a child growing up in Lewisville, Texas, but he has yet to open up now that he's in the NFL and playing for a coach he has known since he was 15.

"Y'all have interviewed him, right?" Kingsbury asked. "What does he usually give y'all?"

Not much.

"It's the same," Kingsbury said. "That's what he is and who he is. I guess he thought he was going to be here his entire life, so it's just the next step for him. I've said it all along: He's a rookie quarterback in the NFL starting Week 1. There's going to be some ups and downs. We're going to make some mistakes. We'll work through those and try to continue to improve together."

Kingsbury can't even get Murray to tell him which plays he wants to run this week.

"It's like pulling teeth with him trying to [get him to] tell me that 'I don't like a play' because he wants to make them all work and that's his attitude," Kingsbury said. "But there's good conversations and after today, walking off the practice field, I'll try to get, 'Hey, what don't you like?' and he'll say, 'I love it all' and we'll move forward. That's how he is.

"He's competitive, and he wants to make it all work. But, yeah, there's definitely those conversations going on. We want to make sure he's as comfortable as possible because it will be a tough challenge. It's hard to step in as a rookie Day 1 and win a football game, and we understand that, so we're going to try to help him as much as possible."

Kingsbury said he might have been "overstating" Murray's quietness a little, but it wasn't by much. And he expects Murray to open up a bit, be more opinionated on plays and start talking more as the season goes on.

"What you see is what you get," Kingsbury said. "He's not going to be over the top, rainbows and sunshine with you, and I like that because that's how he carries himself. He's very confident, very competitive. I like where he's at. I don't ever see him bringing me cupcakes on game day or anything like that. I think he's going to be who he is and we'll continue our relationship."

Murray's confidence that he can run every play stems from his familiarity with Kingsbury's system, which he was first introduced to in eighth grade. From the day he arrived in Arizona, Murray understood some of the operation, execution, reads and terminology, Kingsbury said.

And it has helped Murray adapt to NFL football quicker than most rookie quarterbacks.

"It's not like he's coming in here trying to learn Chinese as a lot of those first-year quarterbacks are," Kingsbury said "Therein lies a little bit of comfort level that maybe some of those other guys didn't have going into Week 1 having to be starters."

All that familiarity will help Murray on Sunday, when he runs the Cardinals' offense for the first time in a game. Kingsbury kept it tightly under wraps during the preseason -- maybe even a bit to the extreme, he admitted Wednesday.

Kingsbury did not run all of his base plays during the preseason, he said, but it won't matter.

"You just rep it in practice, and you make those situations as game-like as possible and take advantage of your practice reps," he said.

But Kingsbury has a strong belief that his version of the Air Raid will work in the NFL because of one primary reason.

"Because it's never been used before in the NFL," Kingsbury said. "I know Chip [Kelly] did a version of what he does, but yeah, there's only one way to find out and it's never been used. Nobody really knows what we're going to do or what it's going to look like and so, we'll kind of take it one game at a time."