DENVER – Heartbreak. Agony. Disgust. Frustration.

Promise.

As the lights went down in Mile High Stadium following the most difficult loss in recent Broncos memory, one beacon shined bright.

24-of-30 for 368 yards, three touchdowns, no interceptions and a 125.6 passer rating.

That’s the line of much-maligned first-year starter Trevor Siemian, the best line and best performance of his young career, all coming against one of the tougher defenses in the NFL. It was a game that reeked of promise for the former seventh-round pick.

“He played like a champ,” said head coach Gary Kubiak after the game.

Kubiak knows a thing or two about champs.

“I think Trevor’s play was tremendous,” added the head coach. “He made big plays across the board. He made some tremendous throws. Wish he could get out of here with the win, but that’s part of being a pro, he has to battle through it. I’m proud of him; he played really well.”

In an odd role-reversal, the loss wasn’t on Siemian and the offense that has been incompetent at times this season; they did more than enough to get the win. Despite a tough first half behind a porous offensive line, the second-year player came out of the locker room guns blazing, putting up an astounding 279 of his 368 yards on the night in the second half and overtime.

It wasn’t just the stats that jumped out at you, though, it was the big plays that have been so lacking this year. A 76-yard touchdown to Bennie Fowler, a 64-yard dime to Emmanuel Sanders, a 35-yard touchdown to Sanders, multiple big throws on third downs, all the plays you expect from your quarterback in this league. Your quarterback of the future.

After the game, though, he only had one thing on his mind.

“Disappointed,” Siemian said when asked directly about his career day. “It stinks to lose, especially going back and forth like that. But really, my hat is off to Kansas City; I thought they battled and battled and played a really good game.”

Pressed again to talk about himself and if his improved health was a reason for his breakout, he went back to the team, saying they all felt fresh.

How about his willingness to take shots downfield?

“Sometimes you have to go stretch the field and let your guys make plays. Those guys stepped up big time and made some big plays for us.”

The quarterback who had just joined a couple guys named John Elway and Peyton Manning as the only players in franchise history to throw for 350 yards and three touchdowns without an interception was unwilling to say one word about his own performance. Not a word. He was disappointed that he couldn’t make one or two more plays to help secure the victory.

That’s the mentality you want out of your leader, but somehow the name Paxton Lynch will still echo in local watering holes, folks wanting to see the young guy. Maybe, though, those folks just watched that young guy grow up right before their eyes.

Yes, shocking as it may be, Trevor Siemian is developing the same way you’re hoping that first-round pick will. In his tenth start, the Northwestern product put down far-and-away the best performance of his career. A performance that we may look back at as the game he got over the hill, the game he arrived.

No, he did not deliver a victory they way the other two quarterbacks mentioned above would in their prime, but don’t forget those two combined to go 7-19 in their first seasons as the guy. Development happens, and it’s happening right before your eyes.

Trevor Siemian: Denver Broncos quarterback of the future?

Hold your laughter.