MORRISSEY: How soon before the Bears cave on Mitch Trubisky?

Bears quarterback Mitch Trubisky passes against the Broncos during a preseason game at Soldier Field on Thursday.(Photo by Jonathan Daniel/Getty Images)

Would it be a waste of time to point out that Mitch Trubisky was playing against second- and third-string defenders Thursday?

A waste of time, an exercise in futility and a buzzkill of massive proportions.

As I was saying, Mitch Trubisky for mayor!

Boy, oh, boy. The Bears’ decision-makers might not think they have a quarterback controversy on their hands, but the city certainly does, and that might end up being the only thing that matters.

Trubisky sent up a bright flare into the night against the Broncos, signaling that he’s here, that he has an arm, that he can run and that, if it’s not too early to make such a proclamation, he’s not starter Mike Glennon. Chicago looked up in wonder. Judging by the joyous reaction, I wouldn’t want to be Glennon or the solar eclipse.

Things couldn’t have gone worse for Glennon in that he wasn’t good and Trubisky was excellent. Glennon surely understands that his job just got exponentially more difficult and that every mistake he makes will be met with cries that Trubisky, the second overall pick in the 2017 draft, should be the starter. Soldier Field in full throat can be an ugly, ugly thing.

If Trubisky keeps playing like this and if general manager Ryan Pace is convinced the offensive line can save him from a beating that will ruin his confidence, the team will have to cave. It just will.

If that seems like a knee-jerk reaction after only one preseason game, it’s because it is. But that’s how good Trubisky was against the Broncos. He did his best work rolling out. He ran the ball well. He was in control. He looked nothing like a rookie.

Glennon, the loneliest guy in the city, stood on the sideline and watched. He could comfort himself with the $19 million he has in guaranteed money.

There are two other knee-jerk reactions, both surely uncomfortable for all the people who thought the Bears reached when they traded up a spot to take Trubisky:

• He’s much, much better than most everyone thought.

• Pace isn’t the blithering idiot he was made out to be on draft night.

Are either of those true? I don’t know, but the fact that we’re discussing it is a reflection of how good Trubisky was and how desperate everyone around here is for a taste of good quarterbacking.

The Bears’ plan is for Trubisky to spend the season watching and learning. He started only 13 games in college at North Carolina. This will be a season of seasoning, and it made sense to many of us until about 9 p.m. Thursday. Why rush the kid when the team isn’t going to be any good anyway?

Ah, but what if? What if he can play? It’s a tease many of us didn’t think we’d have to ponder so soon.

When it comes to the NFL and quarterbacks, it doesn’t take much to send a fan base into heat. If Chicago could stop and take a breath for a second, it might acknowledge that Trubisky didn’t compete against top NFL talent. It might acknowledge there’s still a lot we don’t know about him. But taking a breath would involve breathing, and I’m not sure anyone is doing that yet after Trubisky’s terrific stats against the Broncos: 18-for-25 for 166 yards, a touchdown and a 103.1 passer rating.

And with Glennon’s passer rating coming in at 0.0, well, forget about restraint.

Mike Ditka told TMZ Sports that Trubisky should be the starter in Week 1 and that if he isn’t, ‘‘You’ve got problems.’’

Da Coach is saying what a lot of people are thinking. Trubisky appears to be more gifted than Glennon, and if Pace and coach John Fox decide to start Glennon this season, there might be an uprising in the locker room.

Pace took a lot of heat locally and nationally for drafting a relatively inexperienced quarterback so high. And maybe he’ll turn out to be the rube GM many people accused him of being on draft night. But if he was that stubborn in his belief that Trubisky was worth the pick, he figures to be just as stubborn when it comes to sticking to his plan of easing the quarterback into the NFL.

It’s a smart plan, but it’s a plan that’s going to shatter into tiny pieces if Glennon continues to disappoint and Trubisky continues to progress. Staying the course will be close to impossible when the losses start piling up and the public’s demand for Trubisky’s ascension begins to sound like a mob intent on pillage and plunder.

This should be a time of restraint. One preseason game doesn’t mean a thing. This is a big city. Its denizens should know better than this. Last year, they carried on when Connor Shaw had a 132.0 passer rating in three preseason games. In the eyes of some fans, only a broken leg separated him from certain Bears glory.

Wait a second. Did I just try to compare Shaw to the great Mitch Trubisky?

If you need to reach me, I’ll be in the Witness Protection Program.

Follow me on Twitter @MorrisseyCST.

Email: rmorrissey@suntimes.com