ENGLEWOOD, Colo. -- There were plenty of reasons Gary Kubiak picked Trevor Siemian to start at quarterback for the Denver Broncos -- Kubiak called it "the body of work." But the capstone might have been an eight-play collection in the second quarter of Saturday night's preseason win over the Los Angeles Rams.

The first of the eight plays was a mistake. Siemian threw a pass with just over 10 minutes remaining in the first half that was intercepted by Rams safety Cody Davis. But the fact Siemian, when he was still trying to win the quarterback job, went for the deep ball up the right sideline and put a dart into Cody Latimer's hands roughly 50 yards away showed a certain amount of backbone.

It showed what Kubiak had often talked about as part of he wanted to see from his starting quarterback -- the willingness to make a play and put the ball in a place that gave a receiver a chance.

"I want him to be aggressive," Kubiak said. "He's going to make mistakes. All players are going to make mistakes. He's going to make some. What I really liked is how he came back after it."

It was after that interception when Siemian showed the demeanor his teammates have talked about. His ability to keep cool under pressure might have won him the job.

Trevor Siemian's aggressiveness in the face of the quarterback battle is one reason he ultimately won the job. Ron Chenoy-USA TODAY Sports

"I think his calm demeanor. He's very poised. Even when he comes into the huddle, he's always the same guy. I remember when he first came in, I said, 'You remind me of (Packers quarterback) Aaron Rodgers in the way that he goes about his business," Broncos wide receiver Emmanuel Sanders said. " ... He's not faking who he is. He was going through a lot of pressure situations even going through training camp, making the right throws and the right reads. The coaches were putting a lot of pressure on him. He came into the locker room the next day, still joking and laughing."

Following the interception, and a three-and-out by the Rams’ offense, the Broncos took over on their own 33-yard line. Siemian and the team’s offense went to work.

Siemian hit Sanders for 17 yards on the first play and then completed passes for 5 and 7 yards to Virgil Green and Demaryius Thomas, respectively, putting the Broncos in Rams territory in just three plays. Three C.J. Anderson runs later and the Broncos had a second-and-goal at the Rams' 1-yard line. Siemian hit Green with a 1-yard touchdown pass.

In all it was a seven-play, 67-yard drive for a touchdown following Siemian's mistake. Siemian was 4-of-4 passing for 30 yards on the drive.

"Sometimes I feel like everything is about destiny and this is his destiny to be the quarterback of the Denver Broncos," Sanders said. "This is opportunity. This is his shot. I think he's going to make the most of it."

"Overcoming a mistake, that's part of the game," Kubiak said. "Somebody is going to have to do that over the course of the season, not just the other night. I like the way he responded from that point."

It was a snapshot of what Kubiak wanted to see. A week earlier Mark Sanchez, who was on the inside track to be the starter when training camp opened, was in a similar situation just before halftime against the San Francisco 49ers.

Sanchez had fumbled in the closing seconds of the first half as the Broncos were moving toward a score. The Broncos defense forced a turnover of its own and got the ball back, giving Sanchez and the Broncos' offense a reprieve.

But after two incomplete passes, Sanchez fumbled again -- this time at the 49ers' 21-yard line. It was likely the last snap Sanchez will take for the Broncos, as he did not play Saturday against the Rams and will not play Thursday in the team's preseason finale in Arizona unless Paxton Lynch suffers an injury.

Many in the league expect the Broncos to release Sanchez when the Broncos' roster is cut to 53 players.

While it was Siemian's body of work that won him the job, it was his ability to rebound that helped his cause, an ability to play with freedom with so much on the line.

"I liked the fact that he took his shots," Kubiak said. "He made another poor decision that the kid dropped down in the red zone, so we could have been staring at another (interception) there. That's part of playing the position. You’re not going to grow until you get put in those situations and have to do the right thing. He's aggressive. He believes in himself."