KANSAS CITY, Mo. -- The Kansas City Chiefs were barely competitive in Week 4 when they faced the Steelers in Pittsburgh. They fell behind 22-0 at the end of the first quarter and 36-0 at the end of the third and wound up losing 43-14 as Ben Roethlisberger threw five touchdown passes.

But the Chiefs, at least, will be a different team when they see the Steelers again Sunday at Arrowhead Stadium in the divisional round of the playoffs.

“This team understands how far we’ve come from that game,’’ quarterback Alex Smith said. “For us, we’re certainly not the same team and every week is different. You got to put in the work and, obviously, every Sunday is different. I think that we enjoy that challenge.’’

Rookie Tyreek Hill has emerged as a consistent offensive threat in the second half of the season. Denny Medley/USA TODAY Sports

The Chiefs walked into an ambush in that Sunday night game in early October against Pittsburgh, which was coming off a 34-3 loss to the Philadelphia Eagles. The Steelers announced their intentions on their first play from scrimmage when, despite being backed up near the goal line, they attacked cornerback Marcus Peters, one of the strengths of the Kansas City defense.

Roethlisberger took a deep drop and found wide receiver Sammie Coates, who was covered by Peters, down the sideline for a 47-yard gain. The Steelers didn’t relent until the outcome was no longer in doubt. The Chiefs had repeated breakdowns in pass coverage, some by rookie cornerback D.J. White, who was playing because of an injury to then-starter Phillip Gaines.

The Chiefs clearly weren’t prepared for Pittsburgh’s aggressive playcalling. They shouldn’t be surprised if the Steelers and Roethlisberger play the same way on Sunday.

“You never come out having played the perfect game by any means, so there’s always something to learn," Chiefs coach Andy Reid said recently. "There’s always more work to do, but I will tell you that in the Pittsburgh game they got after us as well as anyone did. You take what you take from it and move on."

The Chiefs have continued to allow a lot of yards, but not the points they allowed against the Steelers. The Chiefs haven’t yielded more than 28 points in any game since losing to Pittsburgh.

2016 NFL Playoff Coverage • Schedule and top stories for every team

• FiveThirtyEight predictions

The Chiefs have changed even more on offense since they saw the Steelers. They were struggling on offense when they went to Pittsburgh, and only in the fourth quarter did they break a streak of 11 quarters with just one offensive touchdown.

The Chiefs continued to have stretches of offensive inconsistency but had two of their best offensive games to end the season, against the Broncos and Chargers.

One big difference has been the emergence of rookie receiver Tyreek Hill as a consistent offensive threat. He played just 18 offensive snaps against the Steelers, about half of what he’s been getting in many of the games since. He did score a touchdown against Pittsburgh on a 9-yard catch, but with the Chiefs behind 36-0.