The Broncos desperately need a new quarterback to halt the horror of ending seasons at Mile High Stadium in front of bored, annoyed fans and tens of thousands of empty seats.

Or maybe not.

Case Keenum hovers just inside or just outside the NFL’s top 20 quarterbacks. His arm is average, but he’s mobile enough and tough enough to run through a crowd of angry defenders for a first down instead of sliding to safety a yard short of the marker.

After leading the offense-challenged Broncos to four straight losses, Keenum will watch the playoffs from his home.

But so will the five highest-paid quarterbacks in the NFL. Aaron Rodgers ($33.5 million) of the Packers and Matt Ryan ($30 million) of the Falcons and Kirk Cousins ($28 million) of the Vikings and Matthew Stafford ($27 million) of the Lions and Derek Carr ($25 million) of the Raiders all failed in their playoff quests. (Jimmy Garoppolo, who earns $27.5 million for the 49ers, was out with a knee injury.)

The quintet won 31 of 80 games. The quintet devoured salary cap. Cousins and Stafford, who earned a combined $55 million, are only slightly superior to Keenum.

The 2015 Broncos showed a team with average quarterbacks can rule the NFL. The Broncos started tottering Peyton Manning in his end days and thoroughly mediocre Brock Osweiler and still conquered every team in sight.

The dominating Super Bowl victory over the Panthers will forever remain a tell-your-grandchildren memory on the Front Range, even if everyone wants to forget the performance of the Manning-led offense.

In the final 56 minutes of the game, Manning threw for a mere 99 yards. His QB rating for the day was a microscopic 56.6. The lure of playing alongside Manning had allowed John Elway to sign free agents and build the violent defense that carried the Broncos to supremacy, but the Manning of 2015 was a shadow of his best days. Peyton in twilight, as he prepared to walk away from a fabulous career, was great at leading and that’s all.

Keenum has already been paid $25 million of his $36 million two-season deal with the Broncos, which means he will earn the equivalent of $11 million next season. That’s not a Black Friday bargain, but it’s a reasonable price for a quarterback who threw 22 touchdowns and seven interceptions for the Vikings in 2017.

He could, if working under the right scheme and surrounded by an offense jammed with talent, become a latter-day version of Jake Plummer, another courageous, average-armed quarterback. Plummer led the Broncos to a 39-15 record as starter from 2003-2006.

The NFL of 2019 is a passing league, but it’s not only a passing league. A dozen quarterbacks threw for over 4,000 yards in 2018, but six of those quarterbacks missed the playoffs. Yardage king Ben Roethlisberger, who passed for a staggering 5,129 yards, will watch the games that matter most.

Elway should pick a quarterback in the upcoming draft, but he should save the Broncos’ No. 10 pick in the first round for the best player available, a strategy that landed Bradley Chubb a year ago, a strategy that can continue to repair a broken roster. All the top QB prospects are gambles, and the Broncos can’t afford to gamble after losing 24 of 36.

Quarterbacks are crucial, no doubt, but it’s not all about the quarterback.