ENGLEWOOD, Colo. — The similarities between the Los Angeles Chargers and the Denver Broncos are absolutely striking.

Von Miller, Joey Bosa.

Bradley Chubb, Melvin Ingram.

Phillip Lindsay, Melvin Gordon.

Royce Freeman, Austin Ekeler.

Emmanuel Sanders, Keenan Allen.

Courtland Sutton, Mike Williams.

Jeff Heuerman, Virgil Green. 

Chris Harris Jr., Derwin James — In terms of an excellent player in the secondary.

Nothing-to-write-home-about offensive line in Denver, nothing-to-write-home-about offensive line in Los Angeles.

There are two major areas that haven’t been mentioned yet. And while you may be thinking it, this article isn’t about coaching.

Anthony Lynn and Vance Joseph aren’t just head coaches with 25 games under their belt at the helm. They both were coordinators for a very short time before being promoted.

In fact, detractors of Joseph often point to the fact he was only a defensive coordinator for one year before becoming Denver’s head coach. Lynn, however, was an offensive coordinator for even less time — taking over coordinator duties during Week 3 of the 2016 season for the Buffalo Bills.

Heck, the two are so similar, they were neighbors back in the day.

That leaves only one major difference between the two AFC West foes.

That difference just happens to be the most important position in sports.

In Los Angeles, the Chargers have their franchise quarterback, Phillip Rivers.

In Denver, they hoped they found an answer in the offseason when they signed Case Keenum to a two-year, $36 million contract.

Though 10 weeks of the NFL season, Rivers is the third-best quarterback in terms of passer rating (115.4) and QBR (76.2).

“The quarterback is playing great football right now,” Joseph said on Wednesday, praising Rivers. “He’s taking care of the ball. He’s got a 115.4 rating.”

On the other hand, Keenum ranks as the 29th-best quarterback in terms of passer rating (83.9) and the 28th-best signal caller in terms of QBR (43.6).

“As time goes along, he’s going to get better, obviously. Being with Billy for a couple of months now, he’s getting a feel for how Billy calls the game and visa-versa,” Joseph also said on Wednesday, this time speaking on his own quarterback and the learning curve he’s going through. “He’s going to play better and better as time goes along.”

According to Joseph himself, Rivers is playing at an elite level right now. Keenum, on the other hand, is still learning and becoming comfortable with his new team and system.

And that’s the glaring difference between a 7-2 red-hot Chargers team and a reeling 3-6 Broncos team.

Through each team’s first nine games, Rivers doesn’t have a single game in which he doesn’t have more touchdowns than interceptions. Keenum has five.

Rivers only has one game in which he had a passer rating below 100 — posting a 97.2 in a Week 4 win against the San Francisco 49ers. Keenum’s best game, in terms of passer rating, was in Week 8 against the Kansas City Chiefs when he posted a 97.9 rating — 0.7 points higher than Rivers’ worst game of the season.

While Keenum’s statistically played better the last five games — posting eight touchdowns to only four interceptions — it still pales in comparison to Rivers’ impeccable 21 touchdowns to a lonely four interceptions over the entire season.

“I think it starts with the quarterback. It always does,” Joseph said, explaining the Chargers’ offense starting with Rivers. “Last couple of years for Philip, he would make some big plays, and he would give plays away also. But he’s not doing that. He is playing smart, efficient football.

That’s precisely why the Chargers have the second-best record in the AFC and have won six-straight games.

This, however, isn’t all Keenum’s fault.

While Keenum is getting a whopping $18 million this year, that’s chump change in today’s NFL for a starting quarterback.

In fact, only two current non-rookie quarterback starters have a lower salary than Keenum.

It’s not that Rivers is getting top-of-the-line money, either, but he’s still making over $20 million per year on a deal he signed in 2015 — well before the $30-million quarterback became the norm.

After his contract expires in 2019, if Rivers wants to continue playing — and nothing indicates the 36-year old won’t want to — he’ll be among the next set of quarterbacks topping $30 million annually.

Following the money, stats and team success, Keenum is playing close to his pay grade, while Rivers is greatly exceeding his.

Sunday’s game between the Broncos and Chargers once again exemplifies how the quarterback position is absolutely crucial to a team’s success.