Domonique Foxworth is concerned that if the Texans don't improve the offensive line to protect Deshaun Watson, they will be in danger of missing the playoffs. (0:50)

GREEN BAY, Wis. -- Houston Texans rookie Lonnie Johnson Jr. didn't make any friends on the first day of joint practices with the Green Bay Packers, and he didn't even get to finish the workout because his coach kicked him off the field after the cornerback leveled two players in what was supposed to be a non-tackling session.

"It was a play that developed over there, and it was time for Lonnie to head to the showers," Texans coach Bill O'Brien said.

O'Brien added that it was "not a big deal."

That's not how the Packers felt after Johnson, a second-round pick, drilled Packers rookie tight end Jace Sternberger, whose helmet went flying off. When Johnson stood over Sternberger and flexed, several Packers players came running over to confront Johnson.

Johnson posted a picture of the big hit on Instagram.

"That was unnecessary," Packers receiver Davante Adams said. "You've got plenty of time for that. You can do it in the games and you get fined. Be a coward when you do stuff like that in practice, it's not a good look. We take care of each other up here. I don't know how they practice, I don't know what they do over there, but there's consequences for stuff like that. ... It's a brotherhood across the league, period. I had plenty of times where I could take somebody out but I decided not to because I felt like that's not the appropriate thing to do when we're trying to get better and look out for one another."

Packers tight end Jimmy Graham called it "kind of ridiculous."

"I respect a lot of those guys over there on the Texans; I've played against them quite a bit over my career," Graham said. "Obviously he's a rookie and he needs to know you can't be hitting guys live in practice. That's absolutely ridiculous. And we're not going to stand for that here, obviously. I know his older guys over there are going to be on him about it because my young guy's just running through a zone, obviously. Just run by him. We know you're going to blow him up in a game. This isn't a game. We're going to play on Thursday. You can do that then. It's one of those things, rookie on rookie, but [No.] 32 has to chill out."

Sternberger returned to practice after he was evaluated for a concussion, but Johnson actually delivered another hit -- to Packers receiver Trevor Davis on a kickoff return -- before O'Brien removed him. Davis did not return.

"I thought there was no place for that," Packers coach Matt LaFleur said. "We addressed it. It's an unfortunate deal, because I was pretty clear with our guys we're not doing that stuff."

Packers right guard Billy Turner relayed what LaFleur told his players.

"He was clear with us, and we were clear with him: If they started taking shots on our players, then we're not just going to stand there," Turner said. "We're not punks by any means, and that's what happened. So we were men of our word, just like he was a man of his word."

When asked if the Texans got the same message before practice, LaFleur said: "I can't speak for them, I have no idea. I just know what I saw out there, and that particular play, that's not what we want to be about."

Sternberger said he did not have a problem with the hit, but also did not realize at the time that Johnson celebrated the hit.

"I didn't know the whole second part, the whole flexing thing," Sternberger said. "I guess that's why my teammates were so upset. Yeah, I mean, I don't know what to say about that. I still think it's football. It could've been the exact other way. Everybody's playing aggressive and intense, so it's a good thing."

Turner said he would not be surprised if there's a fight Tuesday on the second day of joint practices.

"I'm not going to say I expect it, but, again, I'm going to protect my teammates at any cost," Turner said.

Johnson did not speak to reporters after practice but posted a response on Twitter, writing: "Not trying to hurt nobody just wanna be great!"

Texans reporter Sarah Barshop contributed to this report.