EUGENE, Ore. » Nothing seems rushed about Marcus Mariota.

Not the way he emerges from practice on a drizzly morning and says “Hello.” Certainly not the way he answers a reporter’s questions, taking a moment to think, his words unhurried.

“I give all the credit to my lifestyle back home,” he says. “Anybody who can relate to being from Hawaii . . . that’s what the mentality is.”

But the laid-back 19-year-old from Honolulu also happens to play quarterback at Oregon, which puts him at the helm of college football’s most frenetic offense.

There is nothing leisurely about the way he orchestrates an attack that features the likes of De’Anthony Thomas and Kenjon Barner. Or the way he ranks among the nation’s top 20 passers in efficiency.

As the undefeated and second-ranked Ducks prepare to face No. 18 USC at the Coliseum on Saturday, it appears their signal caller has something of a split personality.

“I don’t know how it works,” he says. “But it does.”

Coach Chip Kelly explains, “He’s an even-keeled guy, but that doesn’t mean he does things slow or doesn’t think fast.”

From the very start, recruiting Mariota from St. Louis High in Honolulu, Kelly saw a decision maker with a suitably quick throwing release, just the sort of player who could distribute the ball to multiple weapons.

Not that the transition was easy. Mariota recalls feeling culture shock during his first days in practice, which at Oregon can be every bit as hectic as games.

“My head was swimming,” he says.

But the Ducks have an established track record for breaking in new quarterbacks, making the transition from Dennis Dixon to Jeremiah Masoli to Darron Thomas in recent seasons. Kelly doesn’t consider it a big deal, so long as the new guy is surrounded by talent.

These days, that means the lightning-fast De’Anthony Thomas, the reliable Barner at running back and a capable group of receivers.

Once the 6-foot-4 Mariota realized that his job entailed simply getting the ball in their hands and letting them make plays, the learning part became easier. That’s when another facet of his island heritage began to show.

The Hawaiian warrior.

“You have that competitive nature,” he says. “The warrior mentality is always brought out.”

While Darron Thomas led Oregon to a 12-2 record and a victory over Wisconsin in the 2012 Rose Bowl, Mariota impressed his teammates in practice and word began to circulate that the Ducks might have someone special waiting in the wings.

Then Thomas left school early for the NFL and Mariota wasted no time, passing for 202 yards in his team’s spring game and beating out veteran Bryan Bennett for the starting spot during summer camp.

Still, he had much to prove this fall.

This is an athlete who suffers the jitters before every game but tries not to let it show. His older teammates remark on how poised he seems in the huddle.

“Marcus has his own sense of confidence on the field,” senior offensive lineman Ryan Clanton says. “It’s a quiet confidence . . . and if he’s calm, we’re calm.”

In his debut against Arkansas State — an outmanned opponent — Mariota threw for 200 yards and three touchdowns. Against Arizona three weeks later, he racked up 260 yards and two touchdowns.

But passing is only one facet of his game. The Ducks rank third nationally in rushing and their quarterback is part of that equation.

Even as Mariota threw for four touchdowns in a 52-21 victory over Washington this month, Huskies Coach Steve Sarkisian noted: “I thought the biggest thing that was glaring for us was trying to contain the quarterback because he is just so fast.”

The following week, Mariota rushed for 135 yards and a touchdown against Arizona State.

So, on top of everything else — namely, De’Anthony Thomas and Barner — USC’s defense must keep tabs on a quarterback who has completed 68% of his passes for almost 1,500 yards and rushed for 378 through eight games.

“When he gets in the open field, he just runs away from people,” USC Coach Lane Kiffin said. “So you’ve got to do a good job of the first guy tackling him.”

About the only thing that has slowed Mariota down this season is his team’s success. With so many weapons, he must constantly share the ball. And with so many blowout victories, he spends a lot of time watching from the sideline.

Of being removed early from last week’s 70-14 win over Colorado, he says: “My competitive side hates when Coach Kelly tells me I’m done for the game.”

Not that he would dream of showing it. Emotion doesn’t fit the personal style of this even-tempered Hawaiian. Or the way he goes about winning football games.

“When you play calm you play a little better, and when you play relaxed you have more fun,” he says. “And that makes you pretty good.”

Staff writer Gary Klein contributed to this report.