Josh Rosen is remaining confident ahead of his first NFL start, despite having to go up against a tough Seahawks defense. (0:29)

TEMPE, Ariz. -- Now that Josh Rosen is the Arizona Cardinals' starting quarterback, he isn't about to change what got him there. Rosen held his first news conference as a starter on Wednesday. And while his loquaciousness from college seems to have been left behind at UCLA, Rosen showed he can still offer his opinion in a less bombastic way.

"I am me, and I'm not trying to model my game," Rosen said. "I admire quarterbacks, but I don't try to emulate or act like they do. I do me.

"It's gotten me to this point, so why change?"

In Rosen's first start Sunday against the Seattle Seahawks, he'll have control of an offense that sits last in the NFL in points, total yards, yards per game, rushing yards per game, receiving yards per game, net yards per pass attempt, interceptions per pass attempt, first downs per game, third-down conversions, third-down conversion percentage, red zone drives, red zone touchdowns, offensive efficiency, point margin and time of possession.

To improve the offense, Rosen said he'll simply try to run the correct run plays and complete passes. However, the 21-year-old is being given the keys to an offense featuring running back David Johnson and future Hall of Famer Larry Fitzgerald, with a few conditions.

"I can do anything I want," Rosen said. "But, for the most part, a lot of the stuff's built in. So, alerts, checks, all that stuff, we go over it. I'm never just shooting by the hip, but I definitely have some freedom in the offense to do what's got to be done."

Rookie QB Josh Rosen will take over a Cardinals offense that ranks last in several categories. "I think I'm a pretty good overall quarterback," he said, "and I'm looking forward to getting on the field." Norm Hall/Getty Images

Every play Rosen runs, however, will have been vetted by him -- something he has been doing throughout his career.

"I will not run a play on a football field unless I know why we're running it and what we're trying to accomplish," Rosen said. "That's just how I function. I don't run a 4.5 [40-yard dash], so if things go bad, I can't just hit the exit button. So, I like to understand a playbook in its entirety."

And coach Steve Wilks doesn't mind that.

"I saw that from day one when he first got here, even from the rookie minicamp, which is great," Wilks said. "You want guys asking the question, 'Why?' I always try to tell the coaches to make sure we're coaching the why."

Rosen said he got a lot of text messages and phone calls wishing him luck and telling him he deserved it.

When talking about what the Cardinals are getting in him, Rosen said: "For the most part, I'm just trying to complete balls to the receivers, get the ball moving down the field, maybe extend plays a little bit, use my brain."

He also expressed confidence in handling his new role.

"I think I'm a pretty good overall quarterback," Rosen said, "and I'm looking forward to getting on the field."

Rosen saw last week, when he took over for Sam Bradford with 4:31 left in the game, that the NFL, regardless of salaries, is still football.

"Regardless of how much everyone is getting paid around you, it's still football, just wearing different jerseys," Rosen said. "That was probably the most relieving thing getting on the field, was just completing a ball and sort of understanding it's still the same game I've been playing since the third grade."

Rosen said he has been preparing to start every week because "anything can happen."

And something happened.

"It doesn't change my preparation," Rosen said. "I'm always balls to the wall all the time."