Broncos' offseason questions start at coach, quarterback

ENGLEWOOD, Colo. -- The Denver Broncos (9-7) ended their season with an 24-6 win over the Oakland Raiders on Sunday. Here is a look at the season and what's next:

Grade: C-

Season summary: With coach Gary Kubiak poised to step down because of health concerns and the Broncos faced with finding his successor, it's clear this season never quite came together for the defending Super Bowl champs. The Broncos finished .500 or better for the sixth consecutive season, and some of their defensive statistics -- especially against the pass -- were those of an upper-tier team. The Broncos consistently said they would overcome deficiencies to make the postseason. Bottom line, they never had the single-minded purpose of the 2015 team. Things just bothered these players more, whether it was the "noise" of criticism or praise from the outside or injuries or just inconveniences. It's understandable when a title takes the edge off, but though the Broncos had good leaders at a variety of position groups, they seemed to be missing that presence team-wide. Peyton Manning left a significant gap when he retired. On the field, the Broncos' inability to play with any sort of consistency in the offensive line meant a young quarterback took far too many hits. Trevor Siemian's development was stunted as those hits piled up, and it dragged the entire offense down. It is, without question, the biggest football reason the Broncos didn't make the playoffs.

Biggest draft need: If the Broncos want the physical presence that Kubiak and executive vice president of football operations/general manager John Elway have talked about, then the offensive line leads the way. The Broncos were one of the league's worst teams running the ball, and they need better play across the offensive front or neither Siemian nor rookie Paxton Lynch will develop.

Key offseason questions:

Who will lead them? With Kubiak expected to step down because of health concerns, the Broncos are left with their biggest transition since Elway was hired in 2011. The Broncos, who need work on offense, have two young quarterbacks and a defense that will make them an attractive stop. But Kubiak is an important figure in the team's history -- he was on staff for all three titles -- and he is universally liked by players, coaches and staff alike. Replacing him and getting the team back in the postseason mix will be no easy task.

Who is the quarterback? That question will power the offseason. Siemian doesn't always get an objective hearing in the court of public opinion, but he did finish with more 300-yard passing games than Dak Prescott, and it's safe to say Prescott's first year as a starter would have gone far differently behind the Broncos' line. What Siemian did probably won't be appreciated -- perhaps not even by the Broncos' decision-makers -- because of the playoff miss. With Lynch's vast potential, the Broncos are positioned, in terms of developmental prospects, better than almost anyone else in the league. Now comes the hard part of managing it. Siemian has seen what the job takes, and if he attacks the offseason, it will be difficult for Lynch to beat him out, given the learning curve. The Broncos have two potentially high-quality starters who cost less against the salary cap than any other team in the league devotes to the position.

How much can be done with the offensive line? The Broncos have spent in free agency and used draft picks over the past two years on the line, but they have not received the expected return. They have to decide whether it's a talent issue or coaching. The Broncos won't lift themselves out of the middle of the pack until they fix their offensive front. For the past two years, an offense with its roots in the run game and play-action has been able to do neither with any consistency. And they are in the enviable position of having two young, quality quarterback prospects in Siemian and Lynch. But neither will develop into what he can be if he can't set his feet or go through the progressions because the line can't protect him. Nothing has ruined quarterback prospects more than being tossed into an offense too soon with a line that can't protect them long enough to learn.

How honest will the Broncos be? The Broncos got swallowed up in the post-title swirl, and they didn't eat enough of their football vegetables to avoid it. It happens to virtually every Super Bowl winner that doesn't have a Hall of Fame quarterback pushing them through the days that follow the trophy presentation. The Broncos didn't always like how hard Peyton Manning pushed, just like the Patriots might not always like how Tom Brady does. But if a team is going to stay at the front of the line, it's necessary. The Broncos often had a we'll-turn-it-on-at-the-right-time vibe about them this year. They are a high-character team and had moments when they absolutely looked as if they could beat anybody in the league. But they simply couldn't, or wouldn't, stay dialed in, and they finally ran out of time with an ugly Christmas night loss in Kansas City. There was plenty of talk among the Broncos about what other people needed to do to fix things, but the repair will come when they question themselves.