Ryan Clark explains why Jay Gruden will be under pressure in Washington, while Marcus Spears says Kliff Kingsbury will have to prove himself and improve Arizona's offense. (1:57)

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. Except Murray himself.

Murray, who is quiet by nature, might not have opened up to Kingsbury now that he's in the NFL and playing for a coach he has known since he was 15, but he said Wednesday that he is relaxed in the week leading to his first NFL start.

"I'm chilling," Murray said. "Excited for Sunday, obviously, knowing it's a big day for everybody, start of the season. But we want to start it off the right way and that's with a win, so preparing like any other season for me and just going in and just prepare myself for this game."

Nerves? None.

"I'm not nervous right now," Murray said.

But the 22-year-old admitted he might get anxious Saturday night.

"I always like to keep calm and just, you know, be myself and trust the game plan, trust myself, trust my teammates going into it," Murray said. "Go out there, play my game and let the chips fall where they may."

Murray said he hasn't been nervous since his sophomore year at Allen High School in Texas, when he won the first of three consecutive state championships. But he hasn't shared those feelings with Kingsbury, whom he first met when Kingsbury (then the offensive coordinator at Texas A&M) began recruiting him in 2012.

"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."

Murray disagreed.

"If I don't like it, I tell him," Murray said. "I did yesterday."

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."

He and Murray aren't at the cupcake point of their relationship, Murray said. The quarterback then said there's a time and place to joke around. In the team facility, it's business. He'll save the joking around for his off time.

But Murray said he's not the only one whom it's hard to get information from.

"I'd say the same about him," Murray said.

Murray's confidence that he can run every play stems from his familiarity with Kingsbury's system, to which he was first introduced 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 more quickly 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 gamelike 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."