Matt LaFleur’s most important hire after defensive coordinator just might be his quarterbacks coach.

The success of the new Green Bay Packers coach will depend on whether Aaron Rodgers can bounce back from a bad season to perform like the MVP-type player he’d been for most of this decade. LaFleur's choice to be his quarterbacks coach will play a key role working closely with Rodgers every day.

There hasn’t been any news on whom LaFleur is even considering for the role, which makes you wonder if he might have his reported new offensive coordinator, Nathanial Hackett, handle the job, or maybe even do it himself.

“The bread is going to be buttered with Aaron Rodgers,” is how one scout for an NFL team recently put it. “Whatever (LaFleur) makes out of Aaron is how that’s going to roll. It’s kinda that simple.”

Among the issues is whether at age 35 Rodgers still has some of his best seasons ahead of him, like Tom Brady, Drew Brees and Brett Favre did after age 35. Or whether the cumulative physical and mental effect of three injuries (broken collarbone, sprained knee and concussion) in the last 15 months are hastening his decline.

So much is riding on it, because if Rodgers bounces back and is revitalized by a new coach and offensive approach, the Packers’ prospects for the next three or four years look good. If not, LaFleur is in for a tough slog.

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The Packers’ decision to invest in Rodgers last August is off to a rough start because of his play last season, and by the start of the playoffs plenty of observers were questioning whether it’s worth paying any top quarterback the going rate. The defensive-oriented Chicago Bears and Baltimore Ravens looked like threats for deep playoff runs, and Dallas advanced to the divisional round mostly because of its defense.

Yet a couple weeks later three of the quarterbacks in the Final Four are Brady, who’s the best ever; Brees, a sure first-ballot Hall of Famer and Patrick Mahomes, the prohibitive favorite for this year’s MVP. Even Jared Goff is on the fringe of being a top-10 quarterback.

Sure, if you go by average salary, the highest-ranking of the four is Brees at only No. 7. But the Packers, with Rodgers at No. 1, didn’t miss the playoffs because of the shortage of money to spend elsewhere. They missed it because Rodgers no longer believed in his coach’s scheme and play calling and had a bad year.

The Vikings, for that matter, didn’t miss the playoffs because Kirk Cousin’s contract ranked No. 3 on the list and kept them from paying other players. They missed because Cousins isn’t the quarterback they paid him to be.

Even the idea that New England benefits because Brady doesn’t make top-end pay is a misnomer.

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In the last three years, Brady has ranked Nos. 14, 12 and 21 on the quarterbacks pay list, while Rodgers has ranked Nos. 5, 8 and 1. But have the Patriots spent that saved money on other players? The assumption is they have, but in fact, no. Over that time the Packers have spent more on players other than Rodgers ($519 million total) than the Patriots have spent on players other than Brady ($500 million).

The point is, it’s hard to overstate how important quarterback play is in the NFL, even if the occasional team wins big with defense. That’s why, when you have one, you pay him.

Take it from John Elway, this week’s participant in the first person “What I learned” segment of Peter King’s column for NBC Sports. Elway, who is starting his ninth season as an NFL general manager, has been on the quarterback merry-go-round (and out of the playoffs) since winning the Super Bowl in 2015.

“It’s very difficult to (win) year in and year out unless you find a franchise quarterback,” Elway said.

In other words, if LaFleur doesn’t get Rodgers back playing at a high level, it probably won’t matter what else he does.

In his introductory news conference last week LaFleur didn’t reveal much about his recent conversation with Rodgers — the Packers had Rodgers call him after they’d decided LaFleur was their choice for new coach. But in an interview with King, LaFleur shared that they in fact talked about coaching.

“I believe him when he says he wants to be coached, and coached hard,” LaFleur told King.

LaFleur was right when he said last week that he’ll need to lean on his two seasons of working with Matt Ryan in Atlanta, because this will be much different than his last two seasons with developing young quarterbacks (Goff in 2017 and Marcus Mariota last year).

An assistant coach in the league I recently spoke with described coaching in the NFL as 25 percent X's and O's and 75 percent psychology. That will apply here, because any quarterback who has played in the NFL for 14 years, as Rodgers has, knows plenty about X's and O's.

“(LaFleur) better get a good relationship and be able to motivate Aaron,” the coach said. “It’s pushing buttons, and how do you motivate? (Rodgers) is not going to do it because you tell him to do it. You need to motivate and explain it to where it’s their idea, and they want to do it because they think it’s the best thing, not because you think it’s the best thing.”

LaFleur already has made some big decisions in the last week, starting with retaining Mike Pettine to run his defense. But one of the biggest is still out there: Who will coach Rodgers hands-on every day?

It might be a good idea to have Hackett do it, since Hackett won’t be calling plays anyway. Or maybe it’s something LaFleur should just do himself.