ENGLEWOOD, Colo. — Chris Harris Jr. isn't focused on a Halloween party or Chad Kelly's release or any of the other noise that swirled around UCHealth Training Center on Wednesday.

All of his attention is on a game against the Chiefs that he called "season-changing" — and that's where his focus has been since Friday.

"If you didn't study all weekend and get a jump on these boys, then you ain't trying to win," Harris said Wednesday. "I've been studying and focusing on them the whole time. This is a big game. This is a season-changing game. And if you ain't focused on that [instead of] all this other bullcrap that's going on, you're missing the big point of this game. This is a big game that can change our season and get us back rolling."

Harris knows how close the Broncos were in Week 4 to finishing the job against the then-undefeated Chiefs.

With 12:47 to play on "Monday Night Football," the Broncos kicked a 46-yard field goal to take a 23-13 lead. From there, though, Denver let the game slip away. The Chiefs put together a six-minute, 20-second drive that spanned 75 yards to cut the lead to three. The Broncos answered with a three-and-out that took less than two minutes off the clock.

Patrick Mahomes made the most of that ensuing opportunity, driving the Chiefs 60 yards to take a four-point lead with 1:39 to play.

Denver's final drive fell short of the end zone as the Chiefs escaped Broncos Stadium at Mile High with a win.

And it happened, in Harris' eyes, because his team panicked.

"We did great," Harris said Wednesday. "It's kind of like we just went in panic mode in the fourth quarter. Everybody just [needs to] calm down when it gets like that, when we get situations like that. Just don't go in panic mode as a defense. Everybody just calm down and play football and read your keys. That's what really hurt us in that fourth quarter."

The task won't be any easier at Arrowhead Stadium, where the Broncos haven't won since Sept. 17, 2015. If they're going to break that streak, Harris sees a couple of key areas for improvement.