Vikings defensive line coach Brendan Daly doesn't need much time to begin rattling off the coaches who have had a major influence on him. The list is long.

Ken Leonard? He was Daly's coach at Sacred Heart-Griffin High School in Springfield, Ill., a local legend who had a knack for instilling a tireless work ethic in players.

Steve Spagnuolo? He was Daly's boss in St. Louis the past three seasons, a defensive guru who expanded Daly's understanding of schemes and ways to attack various pass protections.

And then there was Joe Hadachek, the offensive line coach at Drake during Daly's days playing tight end for the Bulldogs from 1993 to '96.

"Joe was a hard-nosed, tough guy. A high-energy guy," Daly said. "But he also had tremendous people skills. And he had this unique ability to make every guy in the group feel like their contributions were absolutely vital to the cause."

That concept always resonated. And now that Daly's back for a second stint with the Vikings, it might be as important as ever.

Yes, Daly has inherited an established line, a unit that recorded 40 1/2 of the team's NFL-best 50 sacks in 2011. And sure, Daly already has some success built in, again working with Jared Allen, the franchise's single-season sack king.

Plus, there's six-time Pro Bowl tackle Kevin Williams and ascending end Brian Robison.

But perhaps even more important to the Vikings' future, Daly was brought back last winter with coach Leslie Frazier hoping to squeeze the maximum potential out of a corps of promising yet still unproven players -- guys such as tackles Letroy Guion and Christian Ballard and end D'Aundre Reed.

"I've seen real flashes from those guys," Daly said. "It's been encouraging to see their attitude and sense of urgency."

Powering up

Guion might have the most riding on his shoulders. In March, as free agency opened, the Vikings gave him a somewhat surprising three-year contract that could be worth $9 million, confident he can be the long-term solution at nose tackle.

The coaching staff, thrilled with Guion's athleticism, asked him to use the offseason to trim down, a chore Daly said Guion quickly accepted and "hit out of the park."

Weighing close to 330 pounds in January, Guion is now down around 305, feeling more mobile and breathing better.

That, in turn, has elevated his confidence and drive.

"I think I've grown most with my work ethic," Guion said. "I understand I have to be high energy and high intensity so that as a D-line we can rough some people up."

Daly's role in sharpening Guion's focus should not go overlooked.

"I love B-Daly," Guion said. "He's always a big ball of energy out there. He gives us that extra push and that extra incentive to keep working. I can say, for the entire D-line, I think he's upped our work ethic. He keeps our motors running. Since the spring, that's the biggest thing he has brought."

Guion is not alone in his praise. Allen also commends Daly's liveliness -- which is saying something considering how tight the star defensive end was with Daly's predecessor, Karl Dunbar.

"Honestly, [Brendan] raises your enthusiasm level," Allen said. "He pushes you to that extent ... He's a big advocate of getting your work done and working at a high level. That's what you have to have. When your coach is enthusiastic, it's hard not to be enthusiastic."

Which comes first?

Daly's experience in Minnesota -- he was an assistant under Dunbar from 2006 to '08 -- has eased the transition. But both Allen and Frazier say the 36-year-old defensive line coach also has come a long way since that first stint.

Allen notes Daly's added confidence and the detailed manner in which he is polishing players' techniques. Frazier points to Daly's consistent fire and doesn't think it was purely coincidence that Rams defensive end Chris Long made a huge rise in his three years under Daly's tutelage.

A year ago, Frazier admits, he'd watch the Rams on film when the Vikings had a common opponent and come away impressed by how consistently hard St. Louis' defensive line played.

The belief is Daly's intelligence and enthusiasm will be the match that lights a similar fire with the Vikings.

In many ways, it's a bit of a chicken-and-egg setup.

At present, it's been Daly's passion that seems to have heightened the desire and investment of the D-line. Yet ...

"I love coaching. I love this game," Daly said. "And it's the best part of my day when I get to be around our players. That's what brings the energy out of me."