If there was anyone who could get a trio of quarterbacks to truly open up, it was Peyton Manning.

Manning’s Omaha Productions partnered with NFL Films to make “Quarterback,” an eight-part Netflix docuseries that followed around Patrick Mahomes, Kirk Cousins and Marcus Mariota last season, producing candid results.

The series, for which Manning served as executive producer, went far beyond game highlights, taking the audience inside the quarterbacks’ homes, introducing their wives and kids, and showing intricate details of injury treatment set against the backdrop of the joy and agony of an NFL season.

“Quarterback” the Netflix docuseries by Omaha Productions and NFL Films, debuts on July 12.

In a recent conversation with The Post, Manning explained why the quarterbacks were willing to grant access for this project, when their lives as NFL quarterbacks are already under a microscope with the public.

“The last thing we wanted to be was a distraction, and that was our promise,” Manning said, before deadpanning a joke about Mahomes.

“We hope to continue this show in future seasons. In fact our pitch is, if you do this show, we guarantee you’ll win the Super Bowl and the Super Bowl MVP.”

Peyton Manning hosts 2017 ESPY awards.
Peyton Manning hosts 2017 ESPY awards.
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He noted that the project’s partners at NFL Films have long established “trust” with players and organizations to have on-field access without being “invasive,” adding that players weren’t speaking to the camera every single week, and that they tried to respect boundaries and conduct in-season interviews at critical junctures.

Still, convincing the players to do it required a deft touch.

“I could tell that Patrick wanted to do it, so his kids would know what he used to do and what his life is like, because they’re so young now,” Manning said.

“To tell you about the respect that he has for the organization, he said that I should talk to coach (Andy) Reid first.”

Patrick Mahomes kisses wife Brittany Mahomes.
Patrick Mahomes kisses wife Brittany Mahomes.

Manning told Mahomes to explain to Reid that he wanted to do the show for the future edification of his children, but Mahomes was deferential.

“He said, ‘No Peyton, you tell coach Reid,’” Manning said.

“It was very telling. Here you’ve got the best player in the NFL right now, that could probably say this is what I’m doing, I don’t care whether you like it or not. Instead, he wants me to ask his head coach for permission.”

Reid’s conditions were that his own meetings not be recorded, and Manning had no issues with that.

“There’s a trust factor. I promised all these guys that anything they didn’t want in it wasn’t gonna be in it,” Manning said.

“These guys had to be comfortable with everything. At the same time, we felt like we wanted to tell the story of what it’s like to be a quarterback and all that goes with it.”

Kirk Cousins shares a moment with his son.
Kirk Cousins shares a moment with his son.

The show documented a collaborative relationship between Reid and Mahomes, including one instance where Reid asked Mahomes his opinion about a play call.

The quarterback was excited about the idea and proceeded to throw a touchdown pass in the flat to Travis Kelce.

Manning described Mahomes as “wanting to be coached” — which is a good thing because it wouldn’t be in Reid’s nature not to.

There were some extraordinary glimpses of access.

The viewer gets whisked into scenes both inside and outside of the team facility: Mahomes’ mammoth estate is getting constructed in Kansas City; Cousins speaks to a sports psychologist and gets treatment from chiropractors as he deals with debilitating pain from getting crushed by defenders; Mariota loses his starting job the same week as his wife gives birth and opts for season-ending surgery without consultation from the Falcons.

The access levels ultimately exceeded Manning’s expectations.

“A lot of it was above and beyond what we asked,” Manning said, noting that he had not expected Cousins sharing his meetings with his psychologist.

“That was not part of the deal at all, but he said, ‘No, it’s OK, I want to have this documented.’ I thought it was awesome. It was real. It showed that it’s not all fun throwing game-winning touchdowns on Sundays.”

Marcus Mariota got benched during his time on the Netflix QB series.
Marcus Mariota got benched during his time on the Netflix QB series.

One surprising element of the show is that Mahomes has a potty mouth — he can regularly be seen dropping f-bombs on the sidelines during the heat of the game.

“I think people will be surprised to see that because obviously you don’t really have that access on the field all the time,” said Manning, who made it clear he wasn’t judging Mahomes for the vulgarity.

“My feeling is he doesn’t really start out doing it, but if you poke the bear, look out! This is a competitive guy. A Raiders pass rusher found that out the hard way. He’s looking for things that challenge him.”

The show benefitted from having three quarterbacks on different tiers — Mahomes has the potential to be an all-time great, and Cousins is very good albeit not someone who has yet accomplished much postseason success, while Mariota was fighting for his job.

In the situation where Mariota got benched the same week he became a new father, the documentary threaded the needle where it provided both sides of the story — Mariota’s and Falcons coach Arthur Smith’s — in a way that didn’t paint either man as right or wrong.

“That was important to me. I’ve known Marcus since he was in college, and he was a counselor at [the Manning Passing Academy] twice,” Manning said.

“When you sign up for something like this, it’s probably no different than football itself — you sign up for the good and the wins, but as I remind people you sign up for the tough losses, getting beat on a last-second field goal, and everything else.”

The documentary uses a number of sports media voices discussing and opining on the season as de facto narrators, including Colin Cowherd, Rich Eisen, Jason McIntyre, Nick Wright, Kyle Brandt and Peter Schrager.

Cousins in general is an interesting case study in how the sports media works — he’s a four-time Pro Bowler and arguably one of the 10 best quarterbacks in the whole world.

However, he’s often been graded on a harsh curve for his struggles to win in primetime and in the playoffs.

In other words, he’s quite good, but he’s not Mahomes.

Manning explained the rationale in having the media narrate the documentary, and how he thinks Cousins is affected.

“We went through several versions. At first, I went through and actually narrated each episode. I filmed it. It just didn’t make as much sense. It just didn’t fit. They took it out and just had me in the beginning setting the stage. From that point, it was game on. This is what people were saying that week,” Manning said.

“That’s what you sign up for when you play quarterback. You sign up for talking heads to give their opinion. Eli actually helped me with this. I would always read the papers after a good game but I wouldn’t after a bad game. Eli told me, ‘You can’t do that. In New York you just never read it!’

“That really changed my approach. I imagine Kirk has a similar approach. I don’t imagine he and his family are sitting around watching these shows.”