Why are Bears linking Justin Fields’ playing time to Andy Dalton’s performance?

The Bears need to play Justin Fields the second he’s ready.

Instead, coach Matt Nagy is tying the rookie quarterback’s playing time to the play of veteran Andy Dalton, whose last winning season as a starter came in 2015 with the Bengals, when Fields was a high school sophomore.

In reiterating Tuesday that Dalton will be the Week 1 starter against the Rams, Nagy made a subtle tweak to the Bears’ messaging, which had been otherwise consistent since they traded up to draft Fields out of Ohio State in April. Dalton’s play will affect when Fields plays during the regular season, Nagy said.

That makes sense — the Bears are starting Dalton because they think he gives their veteran-heavy roster the best chance to win in Week 1 — but Nagy finally said out loud what had been long presumed: Dalton will have to play well to keep the job.

That wasn’t necessarily the case a month ago. Fields is developing quickly, and the Bears believe he’ll be ready if called upon.

“Big picture, when we talked about this from the very start, we said, ‘Whoever is going to be best for the Chicago Bears,’ ” Nagy said. “And that’s going to obviously deal with production and wins, right? So when you look at this thing, you want to make sure we all support each other with one common goal to win, and offensively to score touchdowns. And Andy knows that, Andy is well aware of that. Andy’s excited for the opportunity to show what he can do with these starters and in this offense. And then . . . every day, we have to evaluate and we have to see where we’re at every single day.”

Let the scorekeeping begin, then, starting in Week 1.

Nagy, of course, benched Mitch Trubisky after 10 quarters and three plays last season when he was 2-0 as the Bears’ starter. It’s fair to wonder: Will wins be the metric by which Nagy evaluates Dalton? Touchdowns? Quarterback production? The mood of the locker room?

“Again, it all comes down to the ‘whys’ — it all does,” Nagy said. “It’s a feel thing.”

Nagy has maintained that Fields’ timeline won’t be affected by any questions about Nagy’s job status or that of general manager Ryan Pace. That’s hard to believe, though. It would only be human nature for Nagy’s “feel” to be influenced by the obvious jolt of adrenaline Fields would give the locker room, the fans and Nagy’s Q-rating, especially if the Bears start the season slowly.

Fields was dynamic in his first preseason game and more ordinary in the second. He’ll start the third preseason game Saturday against the Titans so the Bears can evaluate him — but also because Dalton will sit out, along with most of the other starters.

“As long as we’re open and honest in this thing,” Nagy said. “Andy knows we want to win, we want to score a lot of points, we want to be smart with the football. And he’s a leader, and he’s done that. And he’s worked hard throughout [OTAs] and training camp to get to this point right now. And everyone has done their job.”

Fields included. Nagy said “he passed the test” compared to where rookies are expected to be in their first training camp.

Dalton has been sharp in practice, too. Although he struggled to move the ball in the first two preseason games, he also had few fellow starters on the field.

“You’ve got guys that are just playing great at the quarterback position,” Nagy said. “Now you’ve got to take it into the games, and you’ve got to produce. You have to produce. And we all have to produce.

“So that’s part of the evaluation process. That’s part of us understanding, ‘OK, here’s where we’re at.’ Now here come the live bullets. And where are we going to be at?”