DENVER >> Maybe the Denver Broncos wore their throwback uniforms a week too soon.

Sunday’s matchup between the Broncos (3-2) and Los Angeles Chargers (2-2) at Empower Field pits teams sporting two of the NFL’s top defenses and two of the league’s offenses that are still works in progress.

The Chargers are allowing a league-low 12.5 points per game. Right behind them are the Broncos, who are yielding 14.6 points a game.

Both have bottom-five offenses that are still working out the wrinkles with a new QB (Bo Nix in Denver) or coordinator (Greg Roman in L.A.) as they jockey in the AFC West to see who will be the main chaser of the unbeaten Kansas City Chiefs (5-0), who have won the division eight consecutive seasons.

L.A averages 17 points a game and Denver’s average jumped to 19.2 points thanks to a 34-point explosion against Las Vegas last week — the Broncos’ highest output in 43 games.

Of course, Denver’s defense had plenty to do with that onslaught, which was sparked by star cornerback Patrick Surtain’s 100-yard pick-6 for a touchdown.

“He’s a very good corner,” Chargers quarterback Justin Herbert said. “He’s one of those guys who gets things done. He finds a way. He’s hardly ever out of position.”

Nor are his teammates as Denver defensive coordinator Vance Joseph has done another masterful job even without top tackler Alex Singleton, who will have surgery next week to repair a torn ACL that ended his season two weeks ago.

“They are hardly ever out of position,” Herbert said, echoing his praise of Surtain. “They’re so fundamental and very talented. It’s a great combination for them, especially the way they are able to get after the passer.”

The Broncos rank third in the league with 19 sacks and sixth with eight takeaways, one more than the Chargers have in one fewer game.

“They do a good job keeping everything in front of them,” Nix said. “They don’t give up explosives. They’ve kept everybody to low-scoring games.”

Under first-year coordinator Jesse Minter, the Chargers have allowed a league-low 21 explosive plays (running plays of at least 12 yards, receptions of at least 16 yards) so far, a big turnaround from a year ago when they’d already allowed 37 such backbreakers.

“The game plan is always fun,” said Chargers defensive end Morgan Fox. “It’s never a stagnant game plan. Every game, everything makes sense. And then when we go forward, it’s the energy behind it. And the energy behind the execution is always exciting.”