Under new defensive coordinator Jeff Hafley, one of the more noticeable changes for this Green Bay Packers’ unit — along with switching from a 3-4 to a 4-3 base — will be the emphasis on playing with energy and having an attacking play style.

“We’re going to attack,” said Hafley in a sit-down conversation with Larry McCarren. “I told the players that I want to lead the NFL in effort, and I want to lead the NFL in how hard we play, and I want to lead the NFL in taking the ball away.

“I want people to see the confidence that our players are playing with within themselves and their teammates. And showing how much they care about each other and this team by how hard they play and how hard they run to the ball and the effort that they give.”

When Matt LaFleur set out to find the Packers’ next defensive coordinator, it wasn’t his intention to switch to a 4-3 defense. Now, of course, and as LaFleur acknowledged, having the personnel to make that switch was a big factor in hiring Hafley.

However, before LaFleur even determined that Hafley was the guy, it was his intention to find the right person and personality to help get the most out of this side of the ball.

“If you want your players to bring great energy every day,” said LaFleur, “if you don’t do it as a coach, then there’s a problem there. I can’t demand that out of our guys and not expect that out of myself or our coaches. No matter what you’re coaching. Yeah, the energy is an important piece to that.”

In addition to the juice that Hafley and the rest of the defensive coaching staff is going to bring, Hafley has been lauded by former players for his ability to both teach the game and to make the gameplan simple, so players can react on the football field rather than over thinking.

Another key factor in LaFleur’s decision to hire Hafley was his past experience working with defensive backs.

As we’ve heard LaFleur mention on numerous occasions in the past and Hafley discusses with McCarren, the Packers have to get better at generating takeaways. Last season, the Packers’ seven interceptions were the second-fewest in football.

A game plan that the players are able to better execute on, along with how Hafley leads the practices and meetings throughout the week, will be cruical when it comes to seeing improvement in this area.

But, on top of that, this is going to be a more aggressive defense under Hafley as well. He hasn’t shied away from talking about his love for press-man coverage; while at Boston College, Hafley was very willing to send five and six-man pressures on third downs to help force the issue.

“We prioritize it,” said Hafley on generating more takeaways. “And it’s not just talk, it’s every day in meetings, showing them how we are going to do it and teaching them how we are going to do it. And then it has to show up in practice and then it has to show up in the game. That is priority No. 1, we have to take the ball away.”

Although when it was first reported that the Packers had hired Hafley, there was some initial head-scratching, in large part because he seemed to come out of nowhere.

But now, a few months in, it’s easy to see why LaFleur wanted to have Hafley on his coaching staff, especially considering that there is no time to waste. The window to win is here.

“Fiery, his energy … he’s going to bring it,” said Kenny Clark via Packers.com. “He’s going to challenge everybody – challenge everybody to be great. That’s what you want as a coach. You want them to hold guys accountable.”