Patrick Smith/Getty Images

The Broncos are proud to announce the signing of their new starting quarterback, Case Kubiak!

Oops, make that Gary Keenum.

OK, third time's a charm: Case Keenum. Yeah, that's more like it.

Multiple sources have reported the Broncos and Keenum agreed to a new contract Tuesday. According to Mike Klis of 9News, it's a short-term deal: two years and $36 million, roughly the going rate for a premium "bridge" quarterback who can theoretically keep a team competitive while it grooms a rookie prospect.

The 30-year-old Keenum, a former undrafted rookie and unheralded backup for the Texans and Rams, is coming off a 22-touchdown, 11-win career year for the Vikings. But the Vikings decided to let the quarterback who climbed off the bench and led them to the NFC Championship Game hit the free-agent market without even extending an offer, which reveals a pretty telling reality check about Keenum's actual upside.

Keenum is a gutsy/plucky/spunky journeyman who found himself in the right place at the right time last year. He's a modest upgrade over the Broncos' Travesty Trio of Trevor Siemian, Paxton Lynch and Brock Osweiler, who combined for 22 interceptions and 52 sacks last year. He has leadership qualities, will give the Broncos everything he's got and can provide a rookie with some mentorship.

But $18 million per year is a lot of dough for a cap-strapped veteran team. The Broncos believe they can win now with a Keenum-caliber caretaker, even though they just spent two years proving they cannot.

Charles Robinson of Yahoo Sports reported that Gary Kubiak, former Broncos backup quarterback and head coach who now serves as John Elway's major-domo/consigliere, was "deep in Keenum's corner" during the Broncos' decision-making process. That jibes with the Broncos scuttlebutt which made the rounds at both the Senior Bowl and the combine: The Broncos think they are a solid veteran quarterback away from returning to contention, Elway trusts Kubiak, Kubiak likes Elway and no one was all that jazzed about trying to work Kirk Cousins onto the payroll.

Christian Petersen/Getty Images

That's unfortunate for a few reasons:

The Broncos are not a solid quarterback away from becoming contenders again;

Case Keenum is not very solid; and

Kubiak likes Kubiak-type quarterbacks, while Elway is seeking the next Elway.

Let's start with that last item: the Elway-Kubiak, hero-and-wingman, megawatt talent-and-company man dynamic that dates back to the early 1980s and has defined the Broncos' quarterback situation since the day Peyton Manning retired.

The Broncos selected Lynch with the 26th pick of the first round in the 2016 draft. Lynch was the closest thing to a Young Elway that the Broncos could possibly have acquired: a huge, athletic rocketeer with tremendous upside but a lot to learn. Elway entrusted this obvious heir apparent to Kubiak, then the head coach, and Lynch squared off against pesky pepperpot Siemian for the starting job.

Siemian won that starting job. Lynch was rawer than expected. He earned a couple of midseason starts when Siemian was injured but did not appear in the season finale, after the Broncos were eliminated. Kubiak stepped down as head coach and became Elway's viceroy. Vance Joseph arrived, and it was widely assumed Lynch would claim the starting job in 2017.

Except that Lynch, who may have gotten too comfortable with his redshirt freshman status, was not up to the task in training camp. Siemian, who was already running out of plucky sauce late in 2016, crashed hard after a pair of impressive wins at the start of last season. By the end of the year, Lynch and the Broncos had lost all confidence in each other, Osweiler (on a return engagement after getting jettisoned in 2016) had embarrassed himself for three teams in one calendar year, Siemian was out of supporters and Chad Kelly had inserted himself into the conversation by virtue of being Jim Kelly's nephew and staying off the injury report and TMZ for a few months.

In short, the quarterback confusion stems from the Elway-Kubiak dichotomy. The Broncos keep lurching between wanting to develop a franchise-caliber superstar and trying to win with defense and journeyman professionalism. Elway was clearly irked by Kubiak's decision to stick with Siemian in 2016. But he is still trusting Kubiak's counsel.

Now, Keenum arrives as a safe, caretaker quarterback, the kind defense-oriented coaches like Joseph generally prefer. The Broncos will surely draft a rookie, probably a Baker Mayfield-Josh Allen type with the fifth overall pick. Unless that rookie takes the team by storm the moment he arrives, the same dynamic that plagued the team for two years will continue.

None of this would be a problem if these Broncos were the 2015 Broncos, who were talented enough to drag zombie Peyton to the Super Bowl, or even the 2017 Jaguars or Vikings. As he proved last year, Keenum is capable of getting behind the wheel of a talent-laden team and leading it to the playoffs.

Patrick Smith/Getty Images

But the Broncos are not a contender with a quarterback problem. In reality, they are an ordinary team with an identity problem.

The Broncos have no depth behind wide receivers Demaryius Thomas and Emmanuel Sanders, neither of whom exactly elevated his game to help the quarterbacks last season. The tight end position is a blank slate that the team hopes to fill with medical redshirt Jake Butt. C.J. Anderson is the only running back on the roster worth a carry. The offensive line is a mess, though inconsistent quarterback play made it look worse than it really was. Put it all together and the Broncos offense has the makings of a station-to-station snore, with average quarterbacks who can never count on someone else to make a big play and help them out.

Meanwhile, Keenum is leaving a team that offered two quality receivers and a Pro Bowl tight end to throw to, a deep backfield and a rebuilt offensive line. Keenum is now stuck with the Broncos supporting cast, which is unlikely to get much better if the Broncos draft another quarterback in the first round.

So a team that is not as good as it thinks it is just signed a quarterback who is unlikely to be whom they need him to be. The results will either be a .500 season of Keenum dumping swing passes to Devontae Booker or another year of waiting for a rookie to overcome his caretaker while a segment of the organization (including the GM's confidante, a conservative coach and an impatient veteran core) stubbornly backs the caretaker.

The only person who can fix this mess is Elway. But Elway doesn't appear to understand the problem or realize he is part of it.

Elway keeps swapping coaches in and out, shuffling Kubiak from role to role, bringing coordinators like Mike McCoy back, whiffing on draft picks and sending mixed messages about the Broncos' direction. He began his career as the Broncos' chief decision-maker with some of the boldest moves in the history of free agency: wooing Peyton Manning to Denver, snookering the Jets into a trade during the height of Tebowmania. Since then, he's been presiding over a team that has slowly coasted to a stop.

Now, he's leased a glorified consolation prize of a quarterback for just enough money to hamstring the team's efforts to improve elsewhere. It's the kind of move that sustains mediocrity. And mediocre is the one thing a team helmed by John Elway should never be.

Instead of searching for the next Elway or settling for the next Kubiak, the Broncos need to get serious about rebuilding their roster. Signing a bridge quarterback—even the best of them—only gums up the works and slows down the whole process.

Mike Tanier covers the NFL for Bleacher Report. He is also a co-author of Football Outsiders Almanac and teaches a football analytics course for Sports Management Worldwide. Follow him on Twitter: @MikeTanier.