DENVER — Sixteen points could've been more.

Far more.

That seemed to be Trevor Siemian's take after Sunday's 16-10 win, a game in which the Broncos excelled in the first quarter and struggled offensively the rest of the way. During that first period, the Broncos put up 140 yards and 10 points and earned eight first downs while holding the ball for nine minutes and 21 seconds. Siemian went 7-of-9 for 115 yards, one touchdown and a 155.8 quarterback rating.

But the rest of the way, Siemian added just 64 passing yards to his total as he completed nine more passes.

"It was interesting," Siemian said. "I just felt like we were always, like, one play away from really getting momentum, seizing momentum. We just didn't really have a rhythm. They did a really good job of mixing up coverages and defenses and safety pressure — some good things on their end. They kept us on our toes.

"We've got to find a way to kind of stay in that rhythm, stay on the field and get it to our guys."

There was no place that lack of rhythm manifested itself more than in the red zone, where the Broncos failed to score a touchdown on all four of their official red-zone trips.

Late in the first quarter, a pass interference call on free safety Reggie Nelson gave the Broncos the ball at the Oakland 9-yard line. C.J. Anderson picked up 3 yards on first down and gained another yard on second to move Denver to the 5-yard line. A false start on left tackle Garett Bolles pushed the Broncos back, though, and Siemian was flushed out of the pocket on third down and had to throw the ball away.

The Broncos wouldn't return to the red zone until their first drive of the third quarter, and it wasn't a true red-zone trip. On third-and-7, Siemian scrambled to the Oakland 18-yard line, but that fourth-down play was the only one Denver snapped inside the 20-yard line.

On their next drive, though, the Broncos missed an opportunity to take advantage of positive field position that stemmed from an Isaiah McKenzie punt return. Siemian was sacked by Khalil Mack for an 8-yard loss, and Denver had to settle for a Brandon McManus field goal.

That likely wouldn't be deemed a good sack under Siemian's evaluation method, which he explained following Sunday's game.

"I just think you understand, kind of situationally, you're backed up, you're obviously not taking any sacks," Siemian said. "You're in the red zone, you're really down low and it's third-and-5, you take a sack and you kick a 25-yard field goal vs. a 20-yard field goal. It's not that big of a difference.

"That's something I'm trying to get better at, just kind of having situational awareness. There's times to throw it away, and there's times to take a sack and it's a good sack. Those are things I'm working on. I'll look back and see how I did."

To Siemian's credit, he avoided sacks that would've pushed the Broncos out of field-goal range, and the four he took Sunday were for a combined 24 yards.

There's still room, however, for Siemian and the Broncos offense to improve. The upcoming bye week should give the team plenty of time to evaluate these situations, like the one that came off a failed fake punt in the fourth quarter.

In that sudden-change situation, the Broncos again failed to punch the ball in. After a completion to Emmanuel Sanders brought Denver to the 4-yard line, Siemian had a pass batted at the line of scrimmage that hung in the air until Sanders caught it for a 10-yard loss.

Denver couldn't make up the lost ground, and McManus missed a 29-yard field goal to keep the Raiders within striking distance.

"I think we're hurting ourselves down there," Siemian said. "I've got to watch everything, but got to find a way to get touchdowns instead of field goals — which, I thought the first week, we did a good job of.

"We'll figure it out, we'll clean it up on the bye and be ready to go."