KANSAS CITY, Mo. -- In the light of their season-opening road win over the Los Angeles Chargers, everything seems possible to the Kansas City Chiefs.

“It’s a new season," safety Ron Parker said. “Anytime it’s a new season and you start off the year like this, it’s a good feeling. We want to take the same energy and take the same vibe into Game 2 and see what we can get."

In a lot of ways, Week 2 at the Pittsburgh Steelers will be a far better measuring stick for the Chiefs. Their 38-28 win over the Chargers was, for them, the same old, same old. They’ve beaten the Chargers nine straight times, with six of those games being decided by 10 or more points.

The Steelers, on the other hand, are the team the Chiefs have struggled against. Pittsburgh has beaten the Chiefs three straight times, including once in the playoffs after the 2016 regular season.

The biggest reason for Pittsburgh’s three-game winning streak is the Chiefs' run defense. That unit allowed Le’Veon Bell 144, 170 and 179 rushing yards in those games.

In hopes of improving a lousy run defense, the Chiefs spent a significant amount of resources during the offseason on players who are mainly run defenders. They signed linebacker Anthony Hitchens and nose tackle Xavier Williams as free agents and drafted lineman Derrick Nnadi.

Specifically, it was to help the Chiefs win games like the one against the Steelers.

The Chiefs won’t be facing Bell on Sunday unless he quickly decides to sign his contract and the Steelers decide to put him in their lineup on such short notice. But his replacement, James Conner, looked formidable in the opener against the Browns by rushing for 135 yards and two touchdowns.

“Their other running back is pretty good, too," Chiefs coach Andy Reid said of Conner. “... We’ll play aggressive football. When you play Pittsburgh, that’s how you have to play. We’ve got to be ready for a fistfight."

The early returns for the Chiefs and their run defense aren’t encouraging. The Chargers rushed for 5.6 yards per carry on Sunday and would have done more damage had they not gotten behind early and stayed there the rest of the game, forcing them to try 51 passes.

But the Chiefs are still fitting the new pieces together. Hitchens and the other starting inside linebacker, Reggie Ragland, played little in the preseason because of injuries. One of Kansas City’s top run defenders is safety Eric Berry, who didn’t play against Los Angeles because of a sore heel.

“We’re a physical defense," Hitchens said. “We’ve proven this in practice. It really doesn’t matter if we’ve improved in practice. We’ve just got to show it on Sundays."

Hitchens was in on 15 tackles, two for a loss of yardage, against the Chargers. On those two plays, he covered a lot of ground to get to the ball carrier and make the play in the open field.

“Hitch is something special," said Parker, who didn’t join the Chiefs until the week before the Chargers game. "When I first came in, the first day in the locker room, guys told me, ‘Hey, you’re going to like him.’ I saw it [on Sunday]. I’ve been seeing it all week since we’ve been at practice.

“He’s a playmaker. He’s got a knack for the football. He’s a good, fundamentally sound football player."

Berry would certainly help, too. The Chiefs have said his return could happen any day, but they’ve been saying that for some time.

Berry didn’t play in the preseason and hasn’t practiced since Aug. 11, and he figures to need some time to adjust to game conditions.

“He’s not going to have any problems schematically," defensive coordinator Bob Sutton said. “He knows the system. He’s been in the system. It’s just that little instant reaction time that only comes with playing time and adjusting to the speed of the game. ... He’s a very active player, a sudden player. That part gets rusty when a player sits out for a period of time. The only way that can improve is to get out there. You can’t replicate that in a drill during practice."