DENVER -- The Denver Broncos have done some of their heaviest lifting against the NFL’s elite this season. Yes, they’ve scratched, clawed, battled and gone toe-to-toe as they've pushed three of the league's seven teams with at least six wins -- the Kansas City Chiefs, Los Angeles Rams and the Houston Texans -- to the limit.

And for that they’ve received ...

"Nothing," cornerback Chris Harris Jr. said. "Nothing. Our mistakes kill us. Good teams find a way to win those games, they know how to finish it off. Like I've said, it's something we have to figure out."

The Broncos fell to 3-6 Sunday with a 19-17 loss to the Texans when kicker Brandon McManus' 51-yard kick on the game's last play sailed wide right. It means in four games against the Chiefs (twice), Rams and Texans, the Broncos have lost by a combined 16 points.

In short, they have not been repaid for their efforts. And the seat under coach Vance Joseph continues to be a hot one, as the Broncos are now living with the very real danger of suffering their first back-to-back losing seasons since the early 1970s.

Brandon McManus and the Broncos are searching for that missing piece that will help them close out games against the NFL's top teams. Justin Edmonds/Getty Images

"I don't have the words to explain how much it sucks," quarterback Case Keenum said. " ... It's just getting old saying that we're close."

Since their 2-0 start, the Broncos have gone 1-6. It's reminiscent of last season, when the Broncos started 3-1 before an eight-game losing streak sent them reeling to a 5-11 finish. The team has four road games among its final seven contests and has won just two road games since the start of the 2017 season.

The Broncos say it feels different than last season, though, because how they've been forced, by the fate of the schedule, to slug it out with several of the league's heavyweights. They've shown more, played harder, but the results simply don't reflect it.

There's no relief after the upcoming bye, as the 6-2 Los Angeles Chargers await them with the Pittsburgh Steelers (5-2-1) scheduled the week after. Neither Joseph, nor the team as a whole, have gotten the opportunity to gain their balance, as the Broncos are 8-17 in Joseph's tenure.

"Mistakes just kill us every game," Harris said. " ... We can't mess up too much. ... We have to play smarter football, cleaner football."

"The gut-wrenching loss today is no different than other losses," Joseph said. “I just feel bad for our guys, because they work hard all week just for this one opportunity to win a football game. They haven't stopped working in two years. I want wins for them, for our guys."

After the game, Joseph talked of the loss of center Matt Paradis to a fractured right fibula, as well as players who will be set to return from injuries after the bye who "are going to help us win." He has said every coach in the league should approach every week as if his future depends on it because "that's the business."

The Broncos' players have supported Joseph throughout the struggles, often pointing fingers at themselves and their own mistakes. They did so again after Sunday's loss, and Joseph pointed a finger at himself for deciding to have McManus attempt a 62-yard field goal near the end of the first half that was short and right.

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The miss gave the Texans prime field position at the Broncos' 48-yard line with just enough time on the clock -- 18 seconds -- to move 20 yards and convert a 47-yard field goal that pushed their lead to 16-10.

It summed up much of the Broncos season. They took a chance, they didn't make the plays on offense and the defense can't hold at a key moment in the game. It has been a season of "rinse and repeat" on offense, defense and special teams in that regard.

"As a defense, we need to hold them right there," linebacker Von Miller said. " ... Just little stuff like that. We get Brandon out there for 62, he missed, now defense has to go out there and stop them."

Following the game, the players said Joseph told them to keep working, "keep preparing," and said they'll show up on Monday ready to try again. But the frustrations and the disappointments far outweigh the rest at the moment.

"Guys are fighting, great grit," Harris said. "I don't think that's it -- that's never an issue."

"We give teams hell each and every week," Miller said. "We just have to come out on top."