DENVER -- The best young quarterback on the field here Sunday was the one playing for the home team. The one whose face isn't on any of the TV network promos or magazine covers.

The home team quarterback is the one who threw four touchdown passes in the Denver Broncos' 42-17 thrashing of the Dallas Cowboys. The one whose QBR through two games this year stands at a Pro Bowl-caliber 75.2, whose completion percentage is 65, whose record is 2-0.

So why is it, exactly, that it's so tough for us to believe in Trevor Siemian?

"Maybe because he wasn't drafted in the first round," Broncos wide receiver Demaryius Thomas said. "He comes from Northwestern. He doesn't like talking to the media much. As the season goes on, you may hear people talking about him, but it really doesn't matter."

Not on a day like this it doesn't. Not when Siemian was the best young quarterback in a game that featured Dak Prescott. The Broncos' reputation is that of a team that can win with defense as long as the quarterback doesn't screw it up. But if you think this is one of those teams on which the defense resents the quarterback because it does all the work and he gets the glory, think again. The Broncos like Siemian -- a lot more than folks on the outside seem to.

"He's smart, and he's super-accurate with the football," Broncos cornerback Aqib Talib said. "He has the poise of an eight- or nine-year veteran. Trev could be a star in this league. If we do what we need to do on defense, Trev is going to be a star this year."

Trevor Siemian completed 22 of 32 passes for 231 yards with four touchdowns and one interception in the win against Dallas. Photo by Isaiah J. Downing/USA TODAY Sports

Look, it's obviously early. The Broncos started 4-0 last season, then lost seven of their last 12 and missed the playoffs. Siemian's Total QBR in 2016 was 49.7. The Broncos haven't played a road game yet this season and there's plenty that still could go wrong. Offensive line injuries are creeping, with rookie left tackle Garett Bolles having left Sunday's game late. Siemian didn't fare well throwing the ball downfield Sunday and still has work to do in that area. He and the Broncos' offense have been a little leaky with the turnovers late in both of their games.

Moreover, this is a town whose Super Bowl titles were delivered by John Elway and Peyton Manning -- a town where the expectations for quarterbacks are snowcap-high -- and something about Siemian always seems to have not looked the part. He was the Broncos' second choice as Manning's successor, and even after Brock Osweiler spurned them for the Texans' money, they still drafted Paxton Lynch in the first round. He feels a bit like The Accidental Quarterback -- a guy who got the job mainly by showing up.

But what if he's more? What if he's a talented, accurate thrower of the football who fell to the seventh round because he got hurt in his final year at Northwestern and teams aren't accustomed to looking for quarterbacks at Northwestern in the first place? What if he's a young guy who sat behind Manning as a rookie and learned some stuff, and who's developing into something more than his draft pedigree said he was?

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"You see the progression every week," said Broncos guard Ron Leary, who was blocking for Prescott in Dallas last season. "The men in this locker room, we always have faith in him, so it's just everyone else now seeing it. We have all the faith in the world in Trevor."

In truth, Siemian doesn't have to do much. This Broncos defense showed once again Sunday that it can be the driving force that wins Denver's games. Holding Ezekiel Elliott to 8 yards on nine carries? Intercepting two passes from a quarterback who threw a total of four interceptions all last season? The Broncos are still built to smother and demoralize opposing offenses, meaning the offense has to do just enough to win.

"It's still so early," Siemian said. "We're only two games into the season. I've seen how quickly things can change in this league, and I'm very, very happy, obviously, to start the way we have. But we're going to Buffalo, and Buffalo doesn't care if we've won two games or we're 0-2."

That's true, and things can turn very quickly from week to week in the NFL. But Siemian has shown more since becoming the Broncos' starter than he tends to get credit for showing. And if he's on a path of continued improvement, the Broncos could end up being a dangerous team.