Bears rookie quarterback Mitch Trubisky had a very nice game Thursday against the Broncos.

It was the first preseason game for both teams, of course, and young Trubisky came in after starter Mike Glennon and backup Mark Sanchez were done. He worked against a basic defense, against some defenders who no doubt will be starting careers in different fields once cutdown day arrives.

But so what? No matter the opponent, if you complete 18 of 25 passes for 166 yards with no interceptions and lead three scoring drives in your first NFL game, that’s sweet.

Hoorah for general manager Ryan Pace, who traded up to get Trubisky with the second pick of the draft. Yay for quarterbacks coach Dave Ragone, who has taught Trubisky how to improve. Boola-boola for the Bears’ no-name receivers and offensive line, who allowed Trubisky to shine.

Now make Trubisky the starting quarterback.

Yes, he’s only 22 and started only 13 college games at North Carolina. And the NFL is mean and vicious and eats its young.

Again, so what? Life is hard and then you die. Maybe you’ve heard.

Trubisky ran a 4.67-second 40-yard dash at the NFL combine — the same as athletic Clemson quarterback Deshaun Watson — and his feet never will be faster than they are now. His arm is a cannon.

Sure, he’ll make rookie mistakes. But veterans make veteran mistakes. That’s what the NFL is all about — taking advantage of the other team’s mistakes.

So if Trubisky gets beaten up early, is that not better than getting beaten up late?

Everyone is terrified of starting rookie quarterbacks, as though it’s on par with tossing a bunny rabbit into a python exhibit. Yeah, sometimes the rookie gets squashed.

But I randomly will bring up Dan Marino, Peyton Manning, Andrew Luck, Cam Newton and Dak Prescott, all rookies who had great first NFL seasons. I could bring up others, but you get the point.

If Trubisky is the real deal, what are we waiting for?

The NFL isn’t like Major League Baseball, where it’s fashionable to basically shut down your team for several years, twiddle your thumbs, wheel and deal and tell your fans to hold on because one of these days your team will be — ta-da — rebuilt!

NFL teams can go from the bottom to the top in one year. It happens all the time. Examples: The Colts went from 3-13 in 1998 to 13-3 in 1999. The Rams went from 4-12 in 1998 to 13-3 in 1999 and won the Super Bowl.

Want something more recent? The Colts went from 2-14 in 2011 to 11-5 in 2012. The Chiefs went from 2-14 in 2012 to 11-5 in 2013. And so on.

I’ve heard the Aaron Rodgers cautionary tale a million times: Let your future Hall of Fame quarterback sit for years behind your future Hall of Fame starter (Brett Favre) and have the kid learn the nuances of the game from the master. Right. And Mike Glennon is a Hall of Famer?

No, if the worried people had their way, Trubisky would sit this season and stay healthy. And he’d get antsy and frustrated and, I’m thinking, freak out when a media creature got him to admit he hates gathering butt splinters and is homicidal with pent-up ‘‘Put me in, Coach’’ frustration.

For those who loathe quarterback controversies, there you have it.

Bears coach John Fox is on the plank of a pirate ship with the clock ticking and the ocean beckoning. He can’t preside over another terrible season, such as the 3-13 atrocity in 2016, and expect to stay afloat.

He likely is the one who assured Glennon that he could say, ‘‘This is my year,’’ over and over with confidence. But Fox is also the one who might sink if he sticks with Glennon when everyone knows Trubisky is a better player. (Sanchez is a simply a nice guy with a clipboard.)

You hate to go back on your word, but the NFL is a cruel, semi-moral business. Players often refer to themselves as hunks of meat or chess pieces moved about randomly. Fox can play Trubisky and see where the chips fall. What’s to lose?

If Trubisky gets hurt, that wouldn’t be good. But who doesn’t get hurt in the NFL? It’s a hurt business. Is it better to see him get injured a year from now, three years from now, 10 years from now?

Let this preseason roll along and then do the right thing.

Play the kid.

Just do it.

Follow me on Twitter @ricktelander.

Email: rtelander@suntimes.com

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