The unbeaten Chiefs welcome AFC West-rival Denver to Arrowhead Stadium on Sunday

KANSAS CITY, Mo. (AP) — The Kansas City Chiefs go through long, grueling drives during training camp that just about everyone has come to dread. They often take 18 or more plays and nobody is subbed out, instead forced to fight through utter exhaustion to the end.

It's not so hard on Patrick Mahomes, who mostly stands in the pocket to throw. But it's brutal on everyone else.

“Terrible,” Chiefs wide receiver Mecole Hardman acknowledged.

The diabolical plan of Chiefs coach Andy Reid has a reason, though. The long-drive drills are designed to make the Chiefs learn how to win in the fourth quarter, and ultimately, how to win championships in the fourth quarter of the season. And it's hard to dispute the results. They are 8-0 heading into Sunday's matchup with the AFC West-rival Denver Broncos.

“Coach Reid prepares us for those moments. He prepares us to be in those long drives,” said Mahomes, who practiced without any real trouble after tweaking his ankle in the Chiefs' come-from-behind overtime win over Tampa Bay on Monday night.

“We do those long-drive drills every day. It sucks. There's no other way to say it. But it prepares you to be in those moments,” Mahomes added. “We play our best football in the fourth quarter because we prepare to be playing our best at the end.”

Indeed, the Chiefs have won an NFL-record eight consecutive games when they trailed at any point in the second half.

“They're hard for a lot of the guys. They're hard for the receivers, the D-line, the tight ends. I'm the motivator trying to push them to the finish line,” Mahomes said. “It's for moments like last game, and it's proven. We have been able to play great football in the fourth quarter and end of seasons, and I believe that's a big reason why.”

It's why the Chiefs are unbeaten despite only having the league's fifth-best scoring margin — one spot ahead of the Broncos (5-4), who have the sixth-best despite getting blown out 41-10 by the Ravens last weekend.

“Well, it’s the heart of a champion," Denver coach Sean Payton said. "They’ve been in a lot of closer games this year."

So have the Broncos, though the results have not been the same.

Until their lopsided loss to the Ravens, all three of their defeats — to Seattle and Pittsburgh to open the season and the Chargers a few weeks ago — had been by a touchdown or less.

“You have to take the good things you did at Baltimore, take the things you can learn from, and go into this game and not make the same mistakes over and over, and continue to do the good things that you did well,” Broncos quarterback Bo Nix said. “You can't dwell on the past or worry about what has been. You have to move forward to what is going to be.”

Praising Nix

The Chiefs spent the week lavishing praise on the Broncos' rookie quarterback, who has had some growing pains his season — just 223 yards passing with a pick and four sacks against Baltimore — but has mostly showed plenty of promise.

“He's definitely picking up and really learning the offense. He's starting to read defenses a little better,” Chiefs cornerback Trent McDuffie said. “But the best thing he does is his feet. He's willing to run the ball and pull it on zone reads and scramble and make time for his receivers to get open, and he knows where he wants to put the ball.”

Praising Mahomes

Nix has been watching his Kansas City counterpart going back to his days in college, and he hasn't stopped now that they are in the NFL together. In fact, the Broncos quarterback thinks most of the league is watching everything that Mahomes does.

“He’s the best in the league right now. Everyone is trying to match him,” Nix said. "Everybody’s trying to catch up, I feel like. He does a great job of just being himself, playing within the system and makes plays when his team needs him to.”

Love for Hopkins, too

DeAndre Hopkins continues to get more comfortable in Kansas City's offense following his trade from Tennessee. He had two catches for 29 yards against Las Vegas after just two practices, then starred in the win over Tampa Bay, hauling in eight for 86 yards and two scores. He celebrated the first of them with a dance from “Remember the Titans.”

“He’s finding his stride," Broncos cornerback Patrick Surtain II said. “This past game, he saw a lot more targets and he was able to create a lot more plays for their offense. It’s something we’ll keep an eye on for sure.”

Getting defensive

Denver is allowing just 4.71 yards per play, the second-best mark in the NFL, and has been equally stingy against the run and the pass — ninth on the ground and sixth through the air.

The Chiefs have faced some of the NFL's best offenses this season, but they are getting a defense to rival their own on Sunday.

“Their defense is playing out of their minds,” Reid said.

Turf situation

The Chiefs have poured money into their playing surface and have some of the NFL's best turf specialists at their disposal. But the reality is that Sunday's game will be the third played at Arrowhead Stadium in less than a week.

The Chiefs' game Monday night against Tampa Bay was in a driving rain, and Kansas plays Iowa State in a college game on Saturday.

“I do think the field will be something we have to pay attention to,” Payton said. “The weather for Saturday is heavy rain (in the) forecast, so we’ll have to make sure we’re prepared for that.”