The Denver Broncos hired Gary Kubiak for one reason. Revive the vaunted rushing attack that helped propel John Elway‘s Broncos to back-to-back Super Bowls and deliver at least one to Peyton Manning in orange and blue. Or so they said.

But that goal has so far been easier said than done. Through 13 games, Denver has rushed for more than 100 yards just six times and had a season-low 34 rush yards in a Week 14 loss to Oakland.

Now, following that loss to the Raiders (in a game Denver was leading by 12 and had allowed -12 yards at the half), fans and analysts are questioning much more than whether or not Kubiak will be able to breathe life into the run game fast enough to deliver the 39-year-old Manning a second Lombardi trophy and the third in Broncos franchise history.

Manning has missed four consecutive games and will reportedly miss a fifth this week as Denver heads to Pittsburgh, who just beat Cincinnati and knocked Andy Dalton out possibly for the remainder of the season.

Brock Osweiler, who was 3-0 in his first three games of relief of Manning, was sacked five times in the second half in the loss to Oakland and appeared flustered through most of the final 30 minutes as a result.

On Mile High Sports AM 1340, the hosts of The Big, Little and Jake Show say the second-half meltdown wasn’t the result simply of poor play, but of a lack of coaching adjustments, starting with Kubiak.

Raiders defensive end Khalil Mack accounted for all five of Oakland’s second-half sacks, one of which was a strip-sack for a safety. Yet despite his domination against Michael Schofield, Kubiak and the offensive coaches refused to give the inexperienced tackle any help. Additionally, they completely abandoned the running game when it proved ineffective early.

Osweiler was 22-of-29 for 199 yards in the first half, while the running game generated just 25 yards in the absence of C.J. Anderson. Like in the Indianapolis game (in which Denver generated only 35 yards on the ground), Kubiak asked his quarterback to win it with his arm despite consistent, heavy pass pressure.

The result was a restless quarterback in both instances. In Indianapolis it led to interceptions, including one on a potential go-ahead final drive. Against Oakland it caused incompletions. Osweiler finished the day just 31-of-51 with no touchdowns.

Kubiak has spent 31 of the last 33 years as a player or coach in the NFL. It’s mind-boggling to think that he was unable to make mid-game adjustments to match Jack Del Rio, who was widely criticized for his “vanilla” approach during his tenure as Denver’s defensive coordinator.

Denver has two quarterbacks who need help at this point – an aging veteran whose arm and legs aren’t what they once were, and an inexperienced backup getting his first real taste of live game action now that tape is out on him. As the Broncos hit the home stretch of the season (and hopefully the playoffs), Kubiak will need to do more than rely on talent alone to win out.

Listen to the full discussion from the show in the podcast below…

Catch The Big, Little and Jake Show every Sunday afternoon on Mile High Sports AM 1340 or stream live any time for the best local coverage of what’s new and what’s next in Colorado sports.