‘Hard Knocks’ confirms Dan Campbell’s authenticity. But do Detroit Lions players buy it?

He was sweaty. Of course, he was sweaty. How could Dan Campbell not be sweaty?

He stalks the practice field like a, ahem, lion. He drops for pushups and up-downs and if the NFL allowed him to put a helmet and pads on and jump in the drills, well, who would stop him?

But this moment didn’t call for the Detroit Lions head coach to prove he was one of the guys in that way. He just wanted to prove that he had their backs.

And so, after the first practice with full pads — “goin’ live,” as they say — Campbell gathered his team and explained why they were running into each other full speed so early in training camp.

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“Here’s what I got to get across, guys,” he began, his baseball cap tilted toward the back of his head, sweat trickling down his brow, “I had a couple of you look at me like, ‘What the (expletive)? Why are we goin’ live?’ And I swear to God, I’m not a lunatic. I swear to you. And if I absolutely knew we could get to where we need to get without ever putting pads on, I’d do it.”

I believe him. You believe him. No doubt he believes him.

The question is: Do the players believe him? Because their belief is the key to the upcoming season. And the key to his success as a coach.

Talent is critical, obviously. But talent doesn’t matter without buy-in, and Campbell spent last season and is now spending this preseason making sure he gets it.

So, he kept explaining why he wanted his guys in pads so soon, pacing as he spoke, his voice close to cracking, all caught on camera by HBO’s “Hard Knocks:”

“I don’t want to put anybody in jeopardy,” he said. “However, I do know this: The studies say you’ve got to get volume and you’ve got to get intensity before a season comes. You have to. If you don’t, I’m not getting you prepared not only physically, for injury, but also for us as a team to get better.”

Campbell is not a lunatic. He just believes in what he is selling. He is also self-aware.

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That’s obvious in his news conferences, in his self-deprecating manner, in the way he combines intensity and humor. He takes his work seriously, but not always himself.

Still, he was dead serious during this particular post-practice speech.

“I’m doing this because it actually does help you with injury if we do it the right way,” he continued. “And we’re not going to do it every day. But I’ve got a plan, I swear to you. All I think about is you guys. That’s all I think about, man. That’s all I (expletive) think about is you guys, and how I can set you up for the best (expletive) possible … advantage to have a season. I swear to you, man.”

“Hard Knocks” may feel new in these parts because it is new in these parts. What it has revealed — so far — is not new. It’s more that the peek behind the curtain has reinforced what we already knew:

The players like their coach. The players will play for their coach; go watch the last several games of last season. The players have to believe in their coach. Campbell has no charge more important.

And so, he ended his speech with this:

“I need you to trust me.”

And this:

“That’s all.”

And this:

“Please.”

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But he wasn’t begging. He was imploring, and when I asked him the day after “Hard Knocks” aired its first Lions episode, if he sensed the players were coming with him and were buying into why he wants pads and why it’s important to bring in physicality so quickly, he said:

“Absolutely. Absolutely. I really, really believe they trust myself and the staff, that we are doing everything that we can to set them up for success. Physically, but for a long season too, and for wins, to give them — put them in an opportunity to win ball games. I really do believe that.”

Campbell referenced studies that show that hitting in training camp at a certain frequency prepares the body for hitting during the regular season. The players surely have access to similar information. Which means they didn’t need to hear it from him.

But they did need to hear that he was thinking about them. He understands this. He also understands he can’t be a phony when he relays information or tells them why they are doing something.

This is the other thing “Hard Knocks” revealed. Campbell is authentic, along with whatever else you may think, and that is the most critical element of all.

“I am who I am,” he said when asked what he thought about the reaction on social media to the first episode of HBO’s series. “Anytime you do something like this, this is a big thing and you’re going to be out there in the public eye and people are going to gather their own perception of who you are and I’m not changing that. I mean, one way or another I can’t change that, I just got to be myself.”

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No, he is not changing that. Nor could he if he wanted to, I suspect.

This is who Dan Campbell is. This is who the Lions are with him as their coach.

Last season gave us a glimpse. “Hard Knocks” is reinforcing that.

Contact Shawn Windsor: 313-222-6487 or swindsor@freepress.com. Follow him on Twitter @shawnwindsor.