Broncos' Glaring Deficiencies Obvious Due to Raiders', Chiefs' Success

The Denver Broncos are similar to last year's Super Bowl-winning squad. The rest of the AFC West is different, though.

The Kansas City Chiefs and Oakland Raiders are making the Broncos look worse than they are. A 13-10 loss the Tennessee Titans on Sunday at Nissan Stadium didn't help Denver's cause, either.

Before the franchise's bye week, Gary Kubiak's squad looked like a mirror image of the 2015 version, with a dominant defense, efficient offense and quality special teams play. But the team's post-bye performances have not been impressive.

After a 7-3 start, the Broncos have lost two of their last three. Meanwhile, the Raiders can score on anyone, and the Chiefs defense is the league's most dynamic group. The two squads lead the AFC West at 10-3, with the Chiefs holding the tiebreaker.

A year ago, Oakland was still trying to establish an identity as a 7-9 squad. The Chiefs were a playoff team but needed a 10-game winning streak to claim a wild-card spot.

The Broncos are now fighting an uphill battle as tall as the Rocky Mountains due to issues within the roster and the team's upcoming schedule. Kubiak's squad won't raise another trophy trying to use the same formula when it's clearly deficient in certain areas.

Offensively, Trevor Siemian isn't getting much help or being asked to do the same things lately that proved successful for an aging Peyton Manning. The Sheriff played football like Garry Kasparov plays chess; he always knew the right move.

Even when Manning's body failed him, his ability to read, diagnose and process defenses remained second to none. Thus, his ability to place his offense in the correct play on a down-by-down basis was invaluable.

The second-year quarterback learned from the master, and he has some athletic limitations too. But he's now being asked to serve as a gunslinger instead of a game manager.

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Denver's run game is nearly nonexistent.

Kubiak called just nine run plays against the Titans. Justin Forsett, who fumbled the ball for the first time since 2009, and Devontae Booker combined for 18 yards in one of the franchise's worst performances, according to the Denver Post's Nicki Jhabvala:

With C.J. Anderson and Kapri Bibbs on injured reserve, the team's head coach can't rely on the ground game like he did during last year's playoff run.

As a result, Siemian is shouldering the load. Since Oct. 13, the team has asked the Northwestern product to throw the ball 39 times per game. In his 10 regular-season appearances last year, Manning averaged 33 attempts per game. Even when Brock Osweiler played, he attempted 34 passes per contest.

Siemian continues to perform well despite a foot injury that forced him to sit out of the Week 13 matchup with the Jacksonville Jaguars. Upon his return this weekend, Siemian attempted a career-high 51 passes. He completed 68.6 percent of them for 334 yards and a touchdown with no turnovers.

"Trev played a hellvua game," cornerback Aqib Talib said, per Denver 9News' Mike Klis. "We've got to do a better job closing."

The ability to close can come from multiple units. It's not coming from the running game, but the offensive line can pick up the slack. However, offensive tackle, particularly the right side, remains a thorn in the franchise's side.

Kubiak named Donald Stephenson the team's starter at right tackle last week after he and Ty Sambrailo flip-flopped throughout the season.

"Donald has been consistent the last two weeks," Kubiak said Monday, per the Post's Cameron Wolfe. "Hopefully he continues to improve."

He didn't improve. Instead, the 28-year-old played poorly against the Titans. In fact, neither of the team's offensive tackles played well. According to Pro Football Focus, Stephenson and Russell Okung surrendered a combined 10 quarterback hurries.

Without a semblance of a running game and with a shoddy offensive line, the offense is sputtering on money downs, as NFL Research noted:

The issue stems from the pressure being applied on the quarterback, per Pro Football Focus:

If the offense can't maintain the standard previously set, more responsibility falls on the defense.

While the Titans drew the ire of the Broncos defense, the unit didn't respond with the type of performance expected of the reigning champions.

Quarterback Marcus Mariota played his worst game of the season against Denver's secondary, yet the Broncos defensive front didn't hold up at the point of attack.

Tennessee ran for 180 yards and dictated portions of the contest, particularly early, per NFL Research:

Entering Sunday, Denver's defense gave up 32.4 more yards per game than the previous year's effort.

The biggest difference starts with how the Broncos defend the run. The team finished third in 2015 by giving up 83.6 rushing yards per game. That number increased to 127.2 in 2016 without the services of Malik Jackson, Danny Trevathan, Antonio Smith and Vance Walker.

The pass-rushers and secondary are still sensational, but they're now letting teams with strong run games dictate terms.

As such, the path to the playoffs looks dire. Sunday's loss only makes the final three games that much more difficult. The Broncos are in the midst of league's toughest schedule during their final four contests, per ESPN Stats & Info:

With a two-game deficit in the AFC West, clinching a wild card is the team's best hope of a postseason return.

Right now, the Broncos sit sixth overall and own the final playoff spot. Yet the team might need to win at least two of the final three contests against the New England Patriots, Chiefs and Raiders to maintain its current standing since the Miami Dolphins own the same record.

"We've got the right group to do it with," Siemian said, per the team's official video account.

The quarterback's words don't reflect reality. This isn't the same group in the Broncos locker room as the one that hoisted the Lombardi Trophy. There are some missing pieces and definite weaknesses.

The team might have approached this season by trying to win in a similar fashion, but the Chiefs and Raiders turned the tables. The Broncos' chances of capturing another division title are slim, and they'll be fighting for their playoff lives by facing those who have taken their spot atop the AFC West.

Every NFL season is different, and the Broncos must adapt instead of trying to repeat how they achieved last year's success.

Brent Sobleski covers the NFL for Bleacher Report. Follow him on Twitter: @brentsobleski.