CENTENNIAL, Colo. -- It began with promise. Vance Joseph's first season centered on the slogan: reboot not rebuild.

Instead the Broncos regressed, spending the final 12 games getting kicked in the rears. Their eight straight losses matched the longest skid in five decades. The defeats came by average of 16 points per game.

The losses were painful. How they were achieved brought everything into question. Joseph kept his job, if only barely, because general manager John Elway decided he deserved a chance with a better quarterback.

If it were only that easy. As the Broncos begin to gain traction in their offseason workouts, my look at the five players -- Joseph is arguably first on the list, but not a player -- who must deliver for Denver to avoid back-to-back losing seasons for the first time since 1972:

1) Case Keenum, QB:

Let's not miss the obvious. The Broncos quarterback play -- for multiple reasons -- proved disastrous. Only the Browns threw more interceptions than Denver's 22. The Broncos ranked third in sacks allowed with 52, including an NFL-worst 12 in the red zone. Enter Keenum, who leaned on a strong running game to run Minnesota's offense with breathtaking precision. Can Keenum work with coordinator Bill Musgrave to play to his strengths? Keenum is accurate and mobile. And he's already accepted as a team leader. If he approaches last year's numbers -- say 23 touchdowns and 11 interceptions -- Denver will achieve a winning record.

2) Von Miller, OLB:

Miller finished with 10 sacks a year. The knee jerk reaction? He produced a disappointing season. Wrong. He applied more consistent pressure than any edge rusher. It did not result in sacks because he was chipped more than Doritos. It can be argued the Broncos will waste his prime if they don't develop a consistent second pass rusher. The return of a healthy Shane Ray (wrist), Shaq Barrett (hip) and Derek Wolfe (neck) coupled with the drafting of Bradley Chubb should benefit Miller. He will push for Defensive Player of the Year honors with 15-plus sacks.

3) Bradley Roby, CB:

Even with the torrential rain and winds recently, it's hard to forget the shade thrown at the No Fly Zone. Does it still suggest? Of course. As long as founder Chris Harris Jr. plays on the Broncos, the name stays, he told me. And he's right. But will the production remain? The Broncos traded Aqib Talib to the Rams to create a starting job for Bradley Roby. Roby battles inconsistency. However, he has played his best games as a starter. Can he continue this trend and prove he's a core player going forward? His ascension is critical to a defense that depends on its corners to spend more time on an island than Gilligan.

4) Royce Freeman, RB:

Rookies don't belong on these lists. But all bets are off when looking for upticks. With C.J. Anderson gone, Freeman should push Devontae Booker for the starting job. The Broncos want their identity to be simple: a bruising running game that sets up the pass. Booker has shown he can catch passes out of the backfield. In ideal world, these two players with a yet-to-determined third back inspire a more diverse offense.

5) Jared Veldheer, RT:

The Broncos right tackle spot remains a revolving door of ineffectiveness and frustration. Veldheeer brings a reputation as a solid player, but as a left tackle. He has much to prove as a right tackle after struggling last season. Fixing this spot remains imperative for this line to move forward. Veldheer takes the fifth spot, edging out tight end Jake Butt. If the line blocks well, the red zone production will improve. As it gets better, red faces will diminish. It all traces back to quarterback and a more efficient offense. Take care of the ball, and take chances without compromising the defense. Do that, and the Broncos will contend for a postseason berth.