KANSAS CITY, Mo. (AP) The sight of quarterbacks feasting on the Chiefs' defense left an impression throughout the final seven games of the 2013 regular season.
The Chiefs allowed an average of 306 yards passing per game, and finished 25th in the NFL in pass defense last year. That doesn't include Indianapolis Colts quarterback Andrew Luck's 443 yards passing in the playoffs.
The swirling Midwest winds blew in a change from a season ago. The Chiefs are currently ranked seventh in the NFL against the pass.
Quarterbacks, including Peyton Manning and Tom Brady, have not had their way against the Chiefs' defense through five games. The second half of the 2013 season was the needed catalyst for improvement.
''It motivated us a lot because as a secondary you don't want to get too much involved with what everybody is saying,'' defensive back Ron Parker said. ''You just want to worry about the team and us only. There was talk out there about our secondary; we hear that. We just take it in and act like we don't hear it.''
Parker, who has started three straight games for strong safety Eric Berry (ankle), has played a large role on the back end of coverage.
The Chiefs have allowed just 11 passes of 20-plus yards entering Week Seven. That's a far cry from the 63 plays of 20-plus yards the Chiefs allowed in 2013.
''This year we try to focus on keeping everything in front of us and not give up the home run ball,'' Parker said. ''If we give up something short, just make the tackle, no YAC (yards after the catch). The first five games I think we're doing a good job of keeping everything in front of us.''
The Chiefs' five-game performance has the full attention of San Diego Chargers quarterback Philip Rivers, who faces Kansas City on Sunday.
Rivers said he used to account for former Chiefs cornerback Brandon Flowers whenever he played the Chiefs. Flowers plays for the Chargers now.
Now Rivers pays attention to the entire secondary.
''I think (No.) 21 (cornerback Sean Smith) is long,'' Rivers said. ''He likes to get his hands on you. He made a great interception in that New England game and we know he likes to be physical at the line of scrimmage.
''Eric Berry hasn't been in there in a while; he's a guy, a Pro Bowl player that you respect. As a whole, I look at (No.) 39 (free safety Husain Abdullah), (No.) 31 (cornerback Marcus Cooper), (No.) 38 (Parker) has been active in there. It's a group that is playing well together.''
Smith said the entire secondary made a conscious effort to improve throughout the offseason.
''We're definitely communicating more leading up to the game, which is big,'' Smith said. ''We took it upon ourselves to watch a little more film as a unit, so that way we all see the same thing and get each other's mindset on the same page.''
The Chiefs could have Berry on the field Sunday. Though he was limited in practice Wednesday, he seemed on track to return barring a setback.
Still, Smith said how the Chiefs played without Berry is indicative of the talent in the secondary.
''Ron has shown amazing physicality back there at safety,'' Smith said, ''And I didn't know he had that because he's a corner, but he did that. Husain brought toughness and leadership out there. Everybody is showing a little bit of Eric Berry in a sense out there on the field. I think that's been big for us.''
Sunday's game isn't just an AFC West rivalry game, but a contest featuring strength against strength.
Rivers has topped 300 yards passing in two of the past three games, and he tormented the Chiefs in Week 12 last season with 392 yards passing and three touchdowns.
Smith acknowledged Rivers poses a challenge. But the sixth-year cornerback said he and his teammates won't change how they approach the game regardless of opponent.
''We understand the scheme,'' Smith said. ''We're a tight-man team. We have a great pass play rush up front. Just keep your eyes on your work and play with good technique, and if you see something, communicate.''
NOTES: Chiefs coach Andy Reid said strong safety Eric Berry (ankle) ''felt good'' after working out Monday. ''I'm pretty good with him today and we'll see how it goes from there,'' Reid said. Cornerback Sean Smith (groin) was limited during Wednesday's practice. Cornerback Chris Owens (knee) did not practice Wednesday, but is ''day- to-day,'' according to Reid. Running back Cyrus Gray (hand) did not practice Wednesday, but Reid anticipates Gray returning Friday. Wide receiver Donnie Avery, who underwent sports hernia surgery on Oct. 3, remains out.