Playing quarterback is a dicey deal, and counting on one, building an entire offense around him, can be, too.

Take BYU’s Tanner Mangum and Utah’s Tyler Huntley, for example.

One’s hurt, the other’s exposed.

One’s going to miss big games, the other’s taking big hits.

Mangum got off to a slow start this season after showing how productive he could be as a freshman two years ago. He threw for 3,377 yards a few months off an LDS Church mission. Nobody does that. Yet his arm was live enough, his talent great enough to step right in when Taysom Hill got injured and lead BYU to some big victories and a solid season.

This time, with a different set of athletes around him, he’s struggled more and taken a lot of heat from outsiders who say he’s a lousy quarterback.

But he is not a lousy quarterback. He’s the same guy he was when he completed 267 of 446 passes with 23 touchdowns and only 10 interceptions. He didn’t suddenly lose his ability to play the position. He’s got a strong, accurate arm that hasn’t always looked that way over the first three games.

And now he’s hurt. You all saw him hobble off the field Saturday night, and he’s wearing a protective boot.

That’s the problem with the quarterback position. It’s so important to every team, the most important component on most teams. Offensive attacks are built around the QB, offseasons are spent planning for the play of a QB, and then, just like that, things short circuit between an offensive coordinator and a player, and/or a player gets hurt and everything is different than expected.

Mangum looked fine in preseason camp, sometimes playing against BYU’s first-team defense, a group that may not be LSU’s or Utah’s D but that is nobody’s dogs.

And we’ve seen BYU’s offensive woes, the troubles Kalani Sitake said after the LSU and Utah losses that he had to fix.

That fixing will be made more difficult with Mangum out.

Let’s not kid ourselves with the mumbo-jumbo being spoken by coaches about whether or not he’s hurt and how many reps the backups are or are not getting in practice. Mangum is going to miss games. You don’t limp off the field like he did then fire back up to play the next week.

I’d say by the hunch-and-scrunch in his limp he’s gone for at least a month, probably a month-and-a-half.

Anybody who’s ever hurt a foot or had a bad ankle sprain knows what a pain those kinds of injuries are, and they aren’t hurriedly patched together and sent back into battle right away. They take time to heal.

And here’s the point: Coaches have to have a backup quarterback and a backup plan on how to utilize him because chances are neither fat nor slim that he won’t need to play. It happens on fortunate occasions when guys make it unscathed through an entire season. But former Utah offensive coordinator Aaron Roderick said, based on studies he’s seen, making it through without losing a quarterback to some kind of injury for some of the time is a less-than-50-percent shot.

It ebbs and flows, depending on a number of factors, including dumb luck.

And so BYU is left having to make big-time adjustments. In this specific case, not just to fix the already-existing offensive problems, but to do it now without their best quarterback. The Cougars instead will turn to Beau Hoge, a 6-foot-1, 210-pound sophomore out of Kentucky, who before redshirting last year played a bit in 2015, completing 8 of 11 passes for 117 yards and a TD against Wagner. He also ran for two scores.

Which is to say Hoge is a better runner than Mangum, but not the passer. How good he can be … nobody knows. He threw for 3,459 yards and 35 touchdown passes with 865 rushing yards and 26 touchdowns during his senior year of high school.

He’s a different quarterback with different skills than Mangum, so Ty Detmer not only will have to make improvements in the attack all around, he must make adjustments with the quarterback and all the other position groups.

Meanwhile, Utah coaches worry about Huntley and the 37 rushing attempts he’s had in the Utes’ first two games. On the one hand, Kyle Whittingham wants to let Huntley be Huntley, utilizing his speed and mobility to his offense’s advantage. On the other hand, a 188-pound quarterback taking repeated direct shots is not ideal.

Studies argue over whether a running quarterback is more at risk than a quarterback who prefers to stay in the pocket and throw. Just defining who’s who and what’s what is difficult enough, but it takes no Ph.D. to figure that the more times Huntley gets hit in or out of the pocket, the more likely it is that he’ll get hurt.

Don’t want to put any whammy on the talented sophomore because he’s a promising weapon for the Utes, but … however he is utilized, Utah coaches had best have a backup plan with Troy Williams. It’s somewhat easier with the senior because he started all of last season, but he is substantially different from Huntley in the way he plays, which means everyone else on offense must be ready to adjust, too.

Quarterbacks are so essential to a team’s success. The complication is they’re equally as vulnerable.

GORDON MONSON hosts “The Big Show” with Spence Checketts weekdays from 3-7 p.m. on 97.5 FM and 1280 AM The Zone.