First, a stipulation: In the NFL preseason, all stats, scores, and win-loss records are virtually meaningless. (Exhibit A: Two of the most dominant teams of all time, the 1985 Chicago Bears and 2007 New England Patriots, went a combined 36–2 in the regular season and playoffs—and 3–5 in the games that didn’t count.)

The preseason is meant to get players and coaches on the same strategic page, resolve some positional battles, and above all, to keep everyone as healthy as possible for the regular season. These latter two goals are already figuring prominently in the Broncos’ training camp.

The positional contest everyone in Denver wants to talk about is who will be the team’s starting quarterback. Everyone, it seems, except head coach Gary Kubiak, who gets asked about it constantly and usually dissembles and deflects the questions like a campaign trail politician.

Despite a number of serviceable veteran QBs being available this summer, John Elway decided that free agent journeyman Mark Sanchez and third-string holdover Trevor Siemian were competent enough to run the offense until first-round pick Paxton Lynch was ready to be the full-time starter, although most so-called pundits agreed that while Lynch has potential, he’s too raw to contribute right away. (Even we so-called pundits at 5280 predicted that if Lynch ends up starting very soon, it will only be because the team’s 2016 plans went unexpectedly awry.)

The reason Elway felt confident in this approach—and we know this because he’s said it many times—is that he’s convinced his defense can dominate in 2016 the way it did last year. Unfortunately, this assumption is already in serious doubt. After letting free agent lineman Malik Jackson walk in free agency, a reasonable financial decision, his ostensible replacement Vance Walker tore an ACL and won’t play this year. The Broncos also lost linebacker Danny Trevathan to the Bears, and we still don’t know how many games cornerback Aqib Talib might miss if the league decides to suspend him over his bizarre shooting incident in June.

The point is, it’s tough for any NFL unit, no matter how talented or deep, to sustain extreme dominance over multiple seasons, and on paper, the Broncos’ D is neither as talented nor as deep as it was in 2015.

If the team’s defense can’t rise again to those rarefied heights, its QB situation suddenly becomes quite a bit more precarious. Again, preseason games and stats can’t tell you much, but so far Sanchez has looked distinctly Sanchez-ian, turning the ball over three times in two games—and that’s in limited action.

The starting job was always his to lose, and there’s a chance Sanchez might have already done just that. Kubiak just announced that Siemian will start for the second straight week in Saturday’s game. The choice is significant, as preseason week three is typically the “dress rehearsal” for week one of the regular season. (Injury fears keep almost all key players from seeing much action in the last preseason game.) Siemian has moved into the pole position despite faring about as well as you’d expect from a guy who was drafted in the seventh round and spent his rookie season holding a clipboard: adequate but unspectacular.

But the Northwestern alum is merely the latest example of what we might call the Tom Brady Syndrome, so named for the Patriots superstar who was drafted in the sixth round in 2000 and has gone on to become arguably the best QB and inarguably the best draft pick in NFL history. Every year, teams draft “developmental” QBs in the later rounds. Their teams and fans hope these unsung signal-callers can conjure up some magic and become a perennial pro-bowler, or at least a reliable long-term starter. The problem with that fantasy is that there’s exactly one Tom Brady and only a few other mid- or low-round QBs who’ve done anything notable. That hasn’t kept fans throughout the league from thinking their team’s slipped-through-the-cracks guy could be the next Brady-esque unicorn.

This brings us back to Lynch. So far the rookie’s numbers have been solid enough, though he’s compiled them against second- and third-stringers. But he’s also been throwing to his own backups, some who won’t make the team, and that makes it natural to wonder how Lynch would do running the first-team offense. Yes, he’s raw and unproven, but in his first two games he’s shown the arm, the stature (he’s 6’7″), and more than a few flickers of that indefinable field presence you want your team leader to have. That’s why Elway traded up to draft him.

Starting Lynch in week one against the defending NFC Champion Carolina Panthers—whose defense last year was also among the NFL’s best—would be the epitome of teaching someone to swim by throwing him into the deep end of the pool. But until Sanchez or Siemian can inspire even a moderate level of confidence, and especially if the D can’t repeat history, the clamoring among fans, media, and maybe even a few teammates to just let the kid play will only get louder.

Follow 5280 editor-at-large Luc Hatlestad on Twitter at @LucHatlestad.

*Update: Siemian didn’t so much “win” the starter’s job as have it handed to him by Sanchez, who’s now a backup in Dallas after the Broncos cut him over the weekend. (They signed veteran Austin Davis as an insurance policy.) That the defending Super Bowl champs are now being led by a nealry undrafted college QB who charted more INTs than TD passes as an undergrad is reflected in football writers’ dubious preseason projections for the orange-and-blue. These forecasts range from the Broncos barely squeaking into the playoffs to missing them entirely, and so far no one sees the team getting as far as the AFC Championship game. So unless Siemian plays well right away, the calls for Lynch to take the reins will be deafening before the aspen leaves start changing.