The Kansas City Chiefs are 3-0 and alone atop the powerful AFC West division, and it appears this might be their best chance in decades to reach the Super Bowl.

Giving them more reason to smile Sunday after defeating the Los Angeles Chargers on the road, the rival Denver Broncos and Oakland Raiders both lost their road contests and fell to 2-1.

But smiles were hard to come by in the back of the tiny locker room at L.A.’s stadium in Carson, where the Chiefs were packing up after the 24-10 victory.

Linebacker Justin Houston was holding court there.

Houston, in comments to reporters, struck a balanced tone following a victory that was pleasing but not satisfying.

“I feel like we still haven’t put a great game together yet,” he said. “We’ve still got so many plays that we have to get better. We left too many plays on the field. We’re not where we need to be.”

Houston suggested he could’ve provided more help.

He lauded the team’s pass coverage, not his rare speed and power, for his most impactful play: a sack of Philip Rivers – 3.0 seconds after the snap – late in the game on third-and-10, with Kansas City ahead 17-10.

Giving Houston time to defeat a guard, cornerback Marcus Peters forced Rivers to pat the ball by tracking the quarterback’s first target, speedster Tyrell Williams.

However, Houston also suggested that perhaps his teammates lost their focus at times.

“I feel like we were doing too much talking” to others, he said.

There are good reasons for Houston to come off as a grump.

He said the season-ending injury in Week 1 to All-Pro safety Eric Berry forced him to expand his role as a mentor and stabilizer.

“You can’t replace a guy like that,” he said. “The energy he brings, and the plays he makes on the field, you can never replace a guy like that. So, I feel like I have no choice but to try to fill his shoes, which is a tough job to do.”

K.C.’s failures in recent postseasons also may argue for a tough-love approach.

Despite winning nearly 70 percent of their games since coach Andy Reid took over in January 2013, the Chiefs have only one playoff victory to show for the three trips to the Super Bowl tournament.

The Pittsburgh Steelers loom as a heavy-metal obstacle.

Last season, the Steelers routed the Chiefs in Pittsburgh while also appearing to intimidate several Chiefs skills players with hard hits.

In the rematch at Kansas City last January, the Steelers rode their defense and ground game to victory.

Berry’s absence has weakened the defense, but the Chiefs appear improved at running back, where an explosive rookie, Kareem Hunt, has provided huge returns as a rusher and receiver.

Quarterback Alex Smith, at 33, seems to have sharpened his long-range passing, and speedster Tyreek Hill has grown into a reliable pass-catcher.

Houston will be heard from, though, as the Chiefs prepare for Monday’s visit from Washington while knowing the Raiders and Broncos will meet this week.

“Justin is a little more vocal than normal,” safety Ron Parker said. “But, it’s a good thing. Next man up, and we’ve got to figure out a way to keep this thing together.”

Said Houston: “I’m glad we’re winning. I hope the guys appreciate the wins because they’re tough to come by. To get where we’re going, we’ve got to do better.”

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Tom.Krasovic@SDUnionTribune.com; Twitter: SDUTKrasovic