When will Matt Nagy make Justin Fields the Bears’ starting QB? Don’t ask.

Ambiguity and vagueness have become staples of Bears coach Matt Nagy’s playbook when he sits down for a news conference, which leaves everyone listening to decipher what he really means.

He held another round of that game Monday at Halas Hall when the clear question of who will start at quarterback Sunday against the Raiders was met by a variety of roundabout responses rather than a simple two-word answer of ‘‘Justin Fields’’ or ‘‘Andy Dalton.’’

‘‘When we work through this whole process . . . ,’’ Nagy started.

Don’t worry. You don’t have to sit through the whole thing.

Here’s what probably will happen: When the Bears begin their practice week Wednesday, Nagy will say that Dalton still hasn’t fully recovered from the bone bruise in his left knee, so Fields will start again because of the injury. Then there will be a hard-to-follow explanation about why it took all the way till Saturday night to rule out Dalton last week, but it’s obvious enough this week to make the call Wednesday.

That’s not what Nagy said, however. It’s just a prediction sifted from the 500-plus words he offered on the decision.

The most concise reduction of Nagy’s comments is that he wants to start Dalton and will do so if he’s healthy, regardless of Fields’ improvement from his dreadful debut as the starter against the Browns to a much more polished and promising performance against the Lions.

When pressed about whether Fields’ progress will factor into his decision, he steered the conversation back to Dalton being Plan A and the choice hinging on his health. He also gave a generic, inconclusive answer when asked exactly what Fields must do to wrest the job from Dalton permanently.

‘‘I just think, again, what we’re focused on is . . . ,’’ Nagy began.

Just kidding — again. We wouldn’t do that to you.

Nagy has talked a lot about having a plan for Fields, in which it always has been implied that he wants to follow what the Chiefs did by sitting Patrick Mahomes as a rookie.

Still, he has said repeatedly that Fields is ahead of the Bears’ projections. That indicates the plan might change. New information should require new calculations.

We can assume the standard for Fields is that he shows proficiency in the two areas that were always problematic for his predecessor, Mitch Trubisky. Nagy said openly and clearly that Trubisky hadn’t mastered the playbook or reading defenses.

Dalton has a Ph.D. in those disciplines after 11 seasons in the NFL, and that’s why Nagy loves him. But Fields’ elite skills — seen in his 64-yard strike down the middle to Darnell Mooney, 27-yard bull’s-eye to Allen Robinson on the sideline and 11-yard scramble on a third down, among other highlights Sunday — exceed Dalton’s.

So the benchmark for Fields isn’t to eclipse Dalton’s wealth of experience and knowledge in a matter of months but to advance enough in those areas that it becomes profitable for Nagy to live with the inevitable rookie errors in exchange for Fields’ high-end talent.

It seems as though Fields already has reached that checkpoint, but it’s hard to tell how close Nagy is to coming around on that.

He said Monday there are still subtleties of Fields’ game that he must sharpen, and his concern is that opponents will find those flaws on film and exploit them. That quote included a detour about going to bed on time and getting the proper amount of sleep, so it again will be excluded for the reader’s sake.

The ‘‘plan’’ for Fields, like Nagy’s answers lately, has been laborious and undercut how thrilling it’s supposed to be to have a young quarterback like this. Isn’t it usually more fun than this?

It could have been an exciting Monday on which Nagy announced it was time to embark on a new adventure. Instead, it seems more likely he’ll be forced into doing it because of Dalton’s injury.