ENGLEWOOD, Colo.

Trevor Siemian couldn’t be rattled.

Not by the knee injury that ended his college career at Northwestern and scared away everyone but the Denver Broncos, who made him the 250th overall pick in last year’s draft.

Not by his six-month audition for the Broncos’ starting QB job that began with him as the dark horse against veteran Mark Sanchez and first-round draft pick Paxton Lynch.

He wasn’t even unnerved Monday when coach Gary Kubiak informed him he’d won the job — making him the only QB with no passing attempts to take over a defending Super Bowl champion in Week 1.

“I feel like it’s the right decision,” said Kubiak, whose team opens against Carolina on Sept. 8 in a title game rematch. “I believe in this kid and what he can do for our football team.”

Siemian was just as calm after the announcement as he’s been every other day during his remarkable rise from part-time college starter to Peyton Manning’s surprise successor.

“I’m not trying to be Peyton. I could probably get in a lot of trouble trying to be a first ballot Hall of Famer,” Siemian said. “So, those shoes are way too big to fill. I’m just trying to be the best man I can be every day, be the best teammate and take it from there.”

He has no plans to hit up Manning’s phone, either.

“No, I’m sure he’s pretty busy,” Siemian said. “He’s probably got some commercials to shoot or something.”

Siemian says he pays no mind to the stress of the job. And he has no designs on changing his understated style, no plans to switch from the quiet, leader-by-example type to one who’s more vocal.

“I don’t think I want to change who I am or who I am in the locker room. I think we’re really fortunate here we’ve got a lot of great leadership here in the locker room,” Siemian said.

Siemian realizes a lot of NFL fans are asking who he is.

“That’s a tough question,” Siemian said. “I like playing football. I try to be a good teammate, work every day, put my head down and be the best guy I can be.”