Matt Nagy and the Bears offense try to pick up the pieces

You’d think Bears coach Matt Nagy would be eager to accept the excuse that sitting out his starters in the preseason was a reason for his offense’s poor performance in Thursday’s 10-3 loss to the Packers — one of the biggest regular-season letdowns, relative to expectations, in recent Chicago sports history.

It wouldn’t be a crime or even an indictment of Nagy’s coaching expertise. In the NFL today, accepting a little rust in exchange for having a healthy starting lineup to start the season is still a reasonable gambit, even if it costs you a game.

At least it would explain the shoddy, discombobulated effort after the Bears convinced us they’d done everything but play a real game in order to prepare the offense for the regular season.

Instead, Nagy declined the excuse and punted.

In the preseason a year ago, even with Nagy limiting the starters’ snaps, quarterback Mitch Trubisky still got 40 snaps and the offensive line got between 37 and 49, and the Bears opened against the Packers at Lambeau Field like a well-oiled machine, driving 86 yards on 10 plays for a touchdown on their first drive and 60 yards on nine plays for a field goal on their second.

This year, Trubisky and the starters got only three token snaps in the preseason, and the offense — despite being in its second season under Nagy and playing at home instead of on the road — looked out of sync from the start. Running back Tarik Cohen bobbled a pitch on the first offensive play, followed by a number of unforced errors — miscommunications, penalties, bad throws and missed blocks — that had the Bears’ offense in quicksand all night.

But Nagy wasn’t buying the rust factor.

“The bobbled snap with [Cohen], if that has anything to do with him not playing [in the] preseason, I’d be shocked,” Nagy said. “If we hold on to that ball, that might be down the sideline for 40 yards; it was blocked up like a gem. So we didn’t, and that’s just how it goes. . . . We ended up getting a [Packers] penalty on the play, got five yards and got to start over.”

But it wasn’t just that one play. It was the entire game.

“There’s factors that go into that,” Nagy said. “Last year, we were completely brand new in a lot of different ways. There was the unexpected part of last year, as well. There was that this year, as well — I’m not saying there wasn’t. But I think every year is just a little bit different. When I make that decision to not play in the preseason like we did, I open myself to criticism for when you don’t play well. I get that. So that’s a fair question.”

It’s hard to believe that after all these years, playing in the preseason suddenly has no impact on the regular season. Have NFL teams been doing it wrong all these years, needlessly subjecting players to injury in meaningless preseason games, with only the emergence of Hall of Famer Kurt Warner to show for it?

That’s doubtful. Game speed is game speed, and nothing prepares a team for the process of a regular-season game like a preseason game. It’s an adjustment. The Bears adjusted poorly, looking less prepared in the second year of Nagy’s offense at home than they did in the first year on the road.

If it wasn’t rust, Nagy has a bigger problem: an offense that has regressed in its second season when it was expected to take a giant leap. He has 10 days to fix it. And he is sure it will be fixed.

“Absolutely,” Nagy said. “We can’t have that. What just happened [Thursday night], you can’t have.”