If the Bears didn’t replace Mitch Trubisky on Sunday, when would they ever?

Coach Matt Nagy had a three-word answer when asked whether he still was committed to Mitch Trubisky, the third-year quarterback who was absolutely abysmal until garbage time of the 36-25 loss to the Saints on Sunday.

“Yeah,” he said. “Absolutely, yeah.”

Sadly, for the Bears, it’s really that simple. They’re stuck in a dilemma of their own making — playing with someone who, at least right now, might be the worst regular starting quarterback in the NFL.

If Nagy didn’t make a switch Sunday, when would he ever? Before the Bears’ final two scoring drives, Trubisky was 20-for-35 for only 119 yards. He was sacked twice and had a 63.9 passer rating. The rest was window dressing that resulted in him completing 34 of 54 passes for 251 yards, two scores, a 86.3 passer rating — and proof that statistics lie.

Yet replacing Trubisky with backup Chase Daniel “never crossed my mind,” Nagy said.

“Because there’s just so many parts of it,” he said. “And Mitch is a competitor, and I think for all of us, it just was one of those deals where you would love, you would really love it to be able to get the run game going early, early, early so you can do more things, and we didn’t do that.”

It’s been the same all year long. If the definition of insanity is doing the same thing over and over again and expecting different results, the Bears should consider replacing their third-year quarterback. But here’s what’s even more insane: turning the ball over to a 33-year-old backup with five career starts, and hoping for the best.

The most disturbing part of the loss was that the other facets of the team looked so far away from playoff-caliber. The Bears allowed 36 points. They had a punt blocked, another one tipped and a Saints punt return called back because of a penalty.

The Bears are not a slight improvement at quarterback away from being elite.

Three weeks after dislocating his left shoulder, Trubisky returned to action wearing a harness to keep it in socket. The results were ugly. Until the second-to-last play of the first quarter, he led the Bears to one first down. The Bears’ first 11 possessions ended in five three-and-outs, a punt after five plays, two fumbles, a safety, a touchdown and a field goal.

In the fourth quarter, Trubisky appeared to throw the ball away on fourth down, a play he said he didn’t recall after the game. He bemoaned missing Anthony Miller on a third-down pass in the second quarter, but Nagy was quick to point out that the receiver ran the route with an incorrect detail.

Trubisky said his shoulder “felt fine.”

He didn’t seem affected by it, save for the time the Bears, inexplicably, let him run an option play right that exposed his left shoulder to a hit.

“I wasn’t really thinking about it, and I was able to go out there and do my job for the most part,” he said. “And [I] just got to do my job better to help this team.”

Was he rusty?

“Probably a little bit,” Nagy said, “but he wasn’t the only one. I mean, it’s all of us.”

Running back Tarik Cohen agreed.

“That’s my quarterback,” he said. “I’m always going to be 10 toes behind him. Nothing that you see on the field is 100 percent his fault.”

There’s a lot of blame to go around. But the future of the quarterback looks as murky as ever.

“I mean, right now we have no identity,” Trubisky said. “We’re just searching. We don’t have any rhythm. We’re not the offense we were last year, and every year is different, every game is different. We’ve just got to find ways, look within ourselves, and we’ve got to have guys step up.

“All I know how to do is look at myself first; how can I get better this week, how can I step up and make my teammates better, and how can I help fix this offense.”