ENGLEWOOD, Colo. -- Let’s see, the Denver Broncos’ chief football decision-maker, John Elway, was a Hall of Fame quarterback. The head coach, Gary Kubiak, was an NFL quarterback for nine seasons. And Trevor Siemian is the team's current quarterback.

That's plenty of people who believe in the forward pass with a hand in how things go for the Broncos.

So, the notion that the Broncos have decided to avoid the deep ball in the passing game because they’d rather do something else might be more than a little misplaced. Yet, the numbers say the Broncos have had just two completions of over 20 yards in the last three games combined.

“You want to [complete the long ball], but you have to play within the confines of the offense and the defense, what they’re giving you," Siemian said. “Looking back last week, heck, I would have wanted to throw it 50, 60 yards down the field, but when they’ve got guys back there over the top, kind of like an umbrella, you’re not going to do that and look good. You can try it but ..."

Siemian left it at that, but it is decidedly where the Broncos are on offense at the moment. Opposing defenses, especially the Atlanta Falcons and San Diego Chargers in the Broncos’ last two losses, have decided they don’t need to commit extra resources to the line of scrimmage to stop the Denver run game all that often, so those players are staying in coverage. And that means a lot of short passes and not much pop.

The Broncos also haven’t hit 90 yards rushing in their last four games. And Siemian injured his left (non-throwing) shoulder just before halftime of the win in Tampa, so he missed the loss to the Falcons and his mobility and throwing motion were affected when he returned to the lineup against the Chargers.

Throw in right tackle Donald Stephenson’s injury, and the end result has been a struggle to consistently move the ball and do the things on offense the Broncos want to do. While they like what Siemian has done overall -- Kubiak has said, “We need to give our quarterback a chance to operate" -- the inability to run the ball has taken the foundation of Kubiak’s offense and put it on shaky ground.

Without the run game, the play-action pass game is a non-factor, as defenders don’t give the fake much of a look. Because of that, big plays have been hard to come by all around.

“You don’t want to throw it 50 times unless you absolutely have to, but you want to keep balance,’’ said Siemian, who attempted 50 passes in the loss to the Chargers. “I think we’ve been saying that this whole year. You have to make teams defend both, and with what we do offensively, the play-pass and the explosive gains are coming off a run action.''

The Broncos also need the run game to get defenses to commit a safety to the line of scrimmage instead of allowing him to roam in coverage. The Falcons and the Chargers both were content to leave players in coverage and defend the Broncos run game with six- and seven-man fronts.

As a result, the Broncos gained just 4.5 and 4.2 yards per pass attempt, respectively, in those two games -- at least 1.5 yards fewer per attempt than in any other game this season.

“I’ve seen two-deep, three-deep safeties,’’ Siemian said. “Part of that is a product of being down in the game, and the coordinators and defenses aren’t stupid. They’re not going to let one play affect the game once you get to that point.’’

The Broncos trailed the Falcons 10-0 at the end of the first quarter, 20-3 at halftime, and they trailed the Chargers 10-0 early in the season quarter, 21-3 early in the fourth quarter. None of that is conducive to solving issues in the run game or throwing the ball downfield, as the defense simply sits back to protect the lead.

First-and-10 situations have been a struggle for the Broncos, especially of late, but they are averaging 3.2 yards per carry in that down-and-distance situation this season. And that, too, has created long-yard situations on second and third downs. So, again, committing to the run game isn’t always an option.

“We have to make plays on first down," said offensive coordinator Rick Dennison. “That’s the bottom line. You have to move the ball, and first down is a big thing. That’s where we’ve really gone down in the last couple of weeks."

Or as Kubiak put it, "That’s a big down in this league. If not, you’re probably not making third downs, and those are kind of hand-in-hand. But we have to find a way to get more plays. Like I say, if you’re not making first downs and staying on the field, then you’re going to get out of whack."