HOUSTON -- When Brian Cushing was asked to describe defensive coordinator Mike Vrabel, he could only smile.

"Animated," the Houston Texans veteran inside linebacker said.

Whether it's on the field or on the four square court before practice, it's easy to spot the energetic and competitive Vrabel.

"He's always been that guy that brings a lot of energy to the team," outside linebacker Jadeveon Clowney said. "Just having him as defensive coordinator, he's going to push everybody. He's a high-energy guy and we need that every day because some days you come out here and don't want to do anything but you got a guy like that who's always up here, you're going to bring yourself up there with him, just being around him.

"He's never going to let you play down here. Every day he's like ‘You got to bring it,' and I'm just like, ‘Oh, one of them days.' I love it. I like him being our defensive coordinator."

Vrabel said a lot of that energy comes from the passion he feels because he wants to make his players better, just as every coach he's played for -- "from Bill Belichick all the way down to [my] college coach" -- has done for him.

Vrabel joined the Texans as linebackers coach in 2014, and was promoted to defensive coordinator in January. The former New England Patriots linebacker has been a leader since he got to Houston, Clowney said. Now, as defensive coordinator, Texans head coach Bill O'Brien said he thinks that leadership, as well as his football knowledge, has helped him have a good command of the defense on the field and on the meeting room.

"I think he's doing a good job. He's very organized, detailed, works very hard," O'Brien said. "He's got a great way with the players, so I think so far, so good."

Added Cushing: "[Vrabel is] interesting, but extremely knowledgeable. Very smart. His football IQ is through the roof. He's just a football person. He's a football player and now he's a football coach. He is football, 100 percent, all the time.

"He's the kind of coach that's always trying to put his players in the best position possible and it's truly a team defense. Everyone's got to do their job for it to hold up and to be successful, and he does a great job teaching that. We just try to relay it on the field as best as we can."

That "team defense" was ranked No. 1 in total defense last season, and that was with three-time NFL Defensive Player of the Year J.J. Watt on injured reserve with a back injury for most of the season. Because the defense is so good, Vrabel said, there was no need to "put a stamp" on the unit in his first year as defensive coordinator.

"I'm not really trying to put my stamp on our defense," Vrabel said. "I think I'm just trying to coordinate a group of professional athletes that were successful last year as a group. I think that we try to be competitive, we try to be physical, have a winning attitude every day and play with effort and energy.

"Our guys play hard and I appreciate that. So, I don't know if that's my stamp or that's their stamp, but we try to have a culture that is built around competitiveness and winning."