On Sunday, Peyton Manning took the day off. While most of his teammates practiced under the hot August sun, he stood by and was a spectator for the proceedings, watching as Brock Osweiler ran Denver’s first-team offense through day 10 of training camp.

It marked the second time that Manning has enjoyed a mandatory rest day so far this season. And it shouldn’t be the last. If the Broncos are smart, they’d have their quarterback take this coming Friday off, as well; he should stand idly by and watch his unproven and untested backup take the reins during the team’s first preseason game.

Denver’s trip to Seattle shouldn’t be the end of that plan, either. Head coach Gary Kubiak should use a similar strategy on Aug. 22 at Houston, on Aug. 29 when San Francisco comes to town and during the team’s preseason finale on Sept. 3 against Arizona.

In a perfect world, Manning wouldn’t take a single snap during the preseason. The first “live” action he’d see would be on Sept. 13 against Baltimore.

The risk simply doesn’t match the reward. If something were to happen to the Broncos quarterback during a meaningless exhibition game, the season would be lost; a roster filled with 10 Pro Bowl players who have their sights set on a Super Bowl run would be neutered by one catastrophic event.

Meanwhile, the only supposed benefit of his playing is that Manning would get some work running a new offense against actual competition. Of course, that ignores the fact that whatever defense the Broncos are facing in any given preseason game will simply be running base stuff; for the most part, they won’t be game planning for Denver. So there is nothing more to be gained than what can be learned in the controlled environment of the practice field.

And in that setting, the Broncos makeshift offensive line won’t lead to their quarterback getting crushed. During drills at Dove Valley, Manning can’t be touched; on the field against J.J. Watt, Seattle’s fearsome front seven or Arizona’s blitz-happy defense, the work-in-progress group in the trenches is borderline dangerous.

Seemingly every day during training camp, Kubiak and Company have tried a different blend of players along the offensive line. It’s a sign that they are searching for the right combination, proof that they aren’t yet comfortable with many of the pieces along the o-line.

So while the coaches try to evaluate players, and rookies like Ty Sambrailo and Max Garcia attempt to learn the ropes, let Osweiler be the tackling dummy lined up behind center. He’s not a $15 million quarterback that will one day be enshrined in Canton; the season doesn’t depend upon him staying upright.

In addition, the chance to see Osweiler play with the first-team offense against the other team’s No. 1 defense would have an added benefit; it would allow the Broncos to see what they actually have in the fourth-year quarterback. Up until this point, he’s done nothing but play against fringe players in the preseason and hold a clipboard during the regular season; there’s no evidence to suggest that he can or can’t play in the NFL.

Denver needs to figure out the answer to that question, however. They’ve invested a lot of time, energy and money in the former second-round pick; that all goes for naught if they let him walk at the end of this season when his rookie contract expires. But at this point, inking Osweiler to an extension would be a huge gamble; his body of work makes Matt Flynn’s résumé look robust.

So a four-game audition during the preseason would be very helpful. Let Osweiler take every single snap; he could certainly use the work. See what he can do with starters against starters, and with backups against backups. The time to find out if the kid can play – for 2016, ’17 or whenever Manning retires – is now.

While he auditions, the Broncos starting quarterback can observe from the safety and comfort of the sidelines. The league’s most-prepared quarterback doesn’t need any more practice time; it’s a safe bet that he already knows Kubiak’s offense better than anyone who has ever played in it.

There are absolutely zero reasons to play Manning during the preseason, but there is plenty of solid rationale for holding him out. That’s something that coaching staffs in Green Bay, New England and other places where one misstep in August could blow up the entire year have already discovered. Here’s hoping Kubiak has the same realization.

The Summer of Brock should continue. At least until Sept. 13.