Vontae Davis’ recent demotion was, at least in part, due to poor conditioning.

And Chad Johnson’s foul-mouthed antics, should they continue, could jeopardize his place on the team.

Those two revelations were by far the most intriguing exchanges of Tuesday night’s season premiere of Hard Knocks, a behind-the-scenes look at the Miami Dolphins.

Here are the salient moments on HBO’s Emmy Award-winning reality TV show:

Davis, the former first-round pick who was expected to start at corner, is for now a second-stringer, and Hard Knocks showed us why. He didn’t enter camp in good enough shape to hang with Joe Philbin’s up-tempo practice. And, he apparently has a small bladder, getting called out for leaving a 75-minute walkthrough to use the men’s room.

“I am tired. I ain’t going to lie,” the microphones catch Davis saying in practice. “I’m going to act like I’m good. I’m taking acting classes. I’m acting not to look tired.”

It didn’t work. In a private conversation, defensive backs coach Lou Anarumo tried to light the motivational fire.

“You can be as good as you want to be, but you’ve got to change your attitude, change your ways,” Anarumo said. “When you don’t want to, that’s the time to press on. Push yourself, get yourself in better shape.”

Davis wasn’t the only one scolded in Tuesday night’s episode. In the aftermath of Johnson’s profanity-laced introductory news conference last week, it didn’t take long for Philbin to catch wind, and voice his approval.

“Yeah, I’d say we’re different,” Philbin responded, when Johnson said they’re different people.

Later, the first-year coach told show producers: “We all have an obligation, we all have a responsibility. He either needs to fall in line or not. It’s pretty simple.”

When asked if such behavior could cost the receiver his job, Philbin responded: “It could, yeah, absolutely.”

Also featured Tuesday, but making far less news:

•  Derek Dennis, who got cut before the first practice — despite dyeing his hair.

•  The three quarterbacks, two of whom will have their hearts broken on national television at some point.

•  And Les Brown, who’s a phenomenal athlete, but “a complete liability in pass pro and run block,” his position coach said.