ENGLEWOOD, Colo. (AP) The Broncos' narrow path to the playoffs grew even more precarious Friday when their leading tackler and top two tight ends were ruled out for this weekend's game against the Chiefs .
The Broncos (8-6) could see their playoff hopes evaporate with a loss to the Chiefs (10-4) on Christmas night.
Winning at Arrowhead Stadium will be harder for the defending champs without safety T.J. Ward, who leads Denver with 87 tackles, and tight ends A.J. Derby and Virgil Green, all of whom sustained concussions against the Patriots last week.
Also, defensive end Derek Wolfe is questionable after missing practice all week with a neck injury and an illness.
Down to just second-year tight end Jeff Heuerman, the Broncos promoted Henry Krieger-Coble from their practice squad Friday and waived No. 3 quarterback Austin Davis.
Rookies Will Parks and Justin Simmons will replace Ward.
''Throughout the weeks Will and I are always in there in base anyways to get the certain looks just in case we have to be thrown into the fire,'' Simmons said.
Safety Darian Stewart said the defensive schemes won't change and he has faith in the rookies, ''but I think that we just need to still be aggressive and be ready to play. It's still a conference game.''
And a must-win.
The Broncos have historically had a hard time winning in December in Kansas City, where they're 3-16.
What holds true in the world of financial investment - past performance is no guarantee of future results - goes for football, too.
They've lost three of their last four and their last two opponents, K.C. and Oakland, are a combined 21-7. But the Broncos believe they can salvage their season and roar into the playoffs as a menacing wild-card.
''We've got two winnable games,'' Pro Bowl cornerback Chris Harris Jr. said. ''I just know this is the game we've got to put it all in and go get a win.''
Another loss to the Chiefs, who won 30-27 in overtime last month in Denver, could erase the defending champs from the playoff picture and hand GM John Elway, the architect of two Super Bowl trips in the last three years, his first non-playoff season since he took over in 2011.
The Broncos find themselves in this spot primarily because of an inadequate offensive line that's had first-year starting quarterback Trevor Siemian constantly on the run and left banged-up running backs on the ground.
While Denver's run defense isn't what it was last season, the Broncos' pass defense is even better than it was during their Super Bowl 50 run by several measures.
With the help of an NFL-high 40 sacks, the Broncos lead the league in pass defense and passer rating allowed (67.5). They're holding opponents to a league-low 53.8 percent completion rate with just 10 touchdowns and 12 interceptions.
Only two of their losses came down to letdowns on defense, against Kansas City and Oakland, which rolled over the Broncos 30-20 last month.
The Broncos held Alex Smith and the Chiefs to an average of just 12 yards on their first dozen possessions in Denver on Nov. 27 only to surrender scores on Kansas City's final three drives.
That, combined with cornerback Aqib Talib's shouting down of Russell Okung when the left tackle tried to address the team in the aftermath of a loss to New England last week, has the defense primed to make good in the rematch.
Making that task tougher are the injuries, including Brandon Marshall's pulled hamstring that will sideline the inside linebacker for the third consecutive week. Corey Nelson, who has had 23 tackles since replacing Marshall, including a career-high 13 last week, will again start in his place.
Heuerman, a third-round pick out of Ohio State in 2015 who missed his rookie season with a knee injury and has been plagued by ankle and hamstring injuries this year, has four catches for 88 yards this season, including two for 40 last week.
''There are always moments in guys' careers where they get opportunities and they don't ever give it back. Hopefully this is one of those moments for him,'' coach Gary Kubiak said.
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