Coach Sean Payton is in danger of being more like Vic Fangio than anyone in Broncos Country would like to admit.

The Broncos have stunk in September with either Payton or Fangio on the sideline.

With his team approaching a fork in the road, with a chance for a signature win or a loss that could send expectations swirling down the drain, Payton tried to get ahead of the narrative for this early AFC West showdown in Los Angeles against the Chargers.

“It’s Week 3,” Payton declared before the Broncos packed up their 1-1 record and departed for California, where the undefeated Chargers await with two division victories already to their credit. “And so I’m waiting for: ‘Is this a must-win game?’”

The Denver media, which gets browbeaten by Payton on a regular basis, dutifully laughed at the coach’s little joke.

Yes, even a knucklehead like me understands it’s impossible to get mathematically eliminated from the NFL playoff race in September.

But it’s not too early to reveal a playoff contender as a fraud.

This is the Broncos’ first big chance to prove they are a team to be taken seriously.

“Look,” admitted Payton, “it’s an important game. It’s a division game. Alright? It’s an important game, obviously. They’re all important.”

Not every date on the regular-season schedule, however, is created equal.

Beat the Chargers in their backyard, and in a year when mighty Kansas City appears to be extremely vulnerable, I would argue it would count as the most important victory during Payton’s short tenure as coach in Denver.

But come away from SoFi Stadium, which ranks as the softest home-field advantage in the entire league, with a loss?

Well, it would be hard to argue that Payton is any better at getting the Broncos ready for the season than Fangio was during his much-maligned tenure as coach from 2019-21.

Lose to the Chargers, and Payton’s record during his three seasons in Denver would be 3-7.

On his way to getting run out of town after three seasons, know what other Denver coach had a 3-7 record during the first month of the season?

Uncle Vic.

No coach in the NFL does smug better than Payton. A swashbuckling pirate by nature, he rattled his saber loudly over the summer, declaring that quarterback Bo Nix was destined to become an elite NFL quarterback and the Broncos were ready to make a run at the Super Bowl.

Well, with the team’s $31.5 million gamble on talented but oft-injured linebacker Dre Greenlaw now officially on the shelf for another month and the acquisition of veteran tight end Evan Engram now looking more like a joke than the joker Payton sought for his offensive playbook, maybe it’s time for Denver’s head coach to zip his lip and get down to serious work.

In addition to a home-field advantage so weak for the Chargers that Courtland Sutton finds it “hilarious” every time a “Let’s go, Broncos!” chant rocks SoFi, here’s hoping there’s a 100-yard rushing day in J.K. Dobbins, who would love nothing more than to prove L.A. was dumb to let him walk as a free agent.

Although he will be hard-pressed to match or beat the performance of Chargers quarterback Justin Herbert, know what could be the break that benefits Nix the most as he tries to find his rhythm as a second-year pro?

What figured to be the Broncos’ most challenging three weeks of the regular season, with a home game against Cincinnati sandwiched between road tests against the Chargers and league champion Eagles, got a little easier when Bengals quarterback Joe Burrow suffered a toe injury requiring surgery.

Even if they drop a game that allows the Chargers to open the season with a 3-0 record against AFC West foes, Denver can come back home and get back to .500 before September ends with a victory against the wounded Bengals.

I don’t, however, have to remind anyone how damaging a 1-3 start would be to the Broncos’ playoff aspirations.

Since 1990, only 14 percent of more than 200 NFL teams that have started the season 1-3 recovered to earn a postseason berth.

So this might not be a must win in L.A.

But lose to the Chargers, and Denver will be staring squarely into the abyss.