Mike Zimmer was known around Cincinnati Bengals headquarters as a gruff, straight-shooting, salty-tongued defensive mastermind with a football focus so intense that he once put off skin cancer surgery until after training camp and even coached three days after his wife, Vikki, died unexpectedly in their Ohio home.

"Sometimes, his emotions come out, but not all the time," said his son, Adam, a Bengals assistant coach. "He's passionate because he wants to be the best at what he does."

The Vikings, who hired Zimmer as head coach Wednesday, are banking on that aggressive mentality to transform a franchise coming off an unexpected 5-10-1 meltdown. As is typical with NFL coaching changes, the Vikings have initiated a personality U-turn at the top after parting ways Dec. 30 with Leslie Frazier, a laid-back leader who went 21-33-1 over three-plus seasons.

Zimmer, 57, was one of seven candidates to interview and 10 that received interest from the Vikings during a three-week search by General Manager Rick Spielman. Zimmer, a 35-year coaching veteran who has never been a head coach at any level, will officially become the ninth head coach in the Vikings' 54-year history when he's introduced at a Friday morning news conference.

"I'm extremely excited to bring a championship to the state of Minnesota and to the great fan base of the Vikings," Zimmer said on a Vikings video release Wednesday night. "Can't wait to get to work."

Zimmer was born into a football-loving family on June 5, 1956. His father, Bill, played at Bradley and signed with the San Francisco 49ers but was injured and never played a regular-season NFL game.

Bill Zimmer was a high school football coach in the early 1970s when Mike was an all-conference star in football, baseball and wrestling at Lockport Township High School in Illinois. Mike went to Illinois State as a quarterback before moving to linebacker because of a broken thumb.

Like Bill Zimmer, an injury ended Mike's playing career, in his case before he left college. It also set him on his path toward a coaching career. That career has been spent strictly on the defensive side of the ball and saw him passed over after five previous head coaching interviews, including a second meeting Monday with the Tennessee Titans.

'Hard Knocks' star

When Wednesday's news broke, Vikings players reached out to their peers to get a better sense of the man most people know only from his curse-filled outbursts on HBO's "Hard Knocks." Zimmer has been on the cable series three times — once in Dallas and twice with the Bengals, including last summer.

At times, cameras also have captured Zimmer's softer side.

Three days after his wife's sudden death, Zimmer coached the Bengals defense in a 17-14 victory over Baltimore. In an emotional postgame scene, Cincinnati head coach Marvin Lewis gave Zimmer the game ball, and he broke down after a brief speech to his players.

"She was the sweetest, kindest, most caring person who'd never say a bad word about anybody," Zimmer told espn.com in a story following Vikki's death.

But Zimmer's usual field presence is a loud, R-rated, no-nonsense coach who isn't afraid to get in his players' faces.

"I talked to [Bengals safety] Taylor Mays and [Vikings receiver] Jerome Simpson, who was there with coach Zimmer," fullback Jerome Felton said. "Coach Frazier and coach Zimmer have different styles, no question about it. But I feel if a person is a straight shooter, that's what matters. Whether you come at that as being a little rough around the edges, like coach Zimmer is, or real laid-back, like coach Frazier, I think players respect that and gravitate toward that.

"At the end of the day, the league doesn't owe you much, but if you at least get a coach that can give it to you straight, you can respect that."

Still, there will be an adjustment period, particularly when training camp starts in July.

"I never heard Leslie curse or even raise his voice," Felton said. "I heard more curse words and yelling from one episode of 'Hard Knocks' than I heard in my whole time here with Leslie. So it's going to be different."

Xs and Os, not PR

An NFL assistant for 20 years, Zimmer has spent the past 14 as a defensive coordinator for three teams. When he was in Dallas, the Cowboys had top-10 defenses whether Zimmer used his preferred 4-3 scheme or the 3-4 scheme that Hall of Fame coach Bill Parcells wanted.

Before Zimmer arrived in Cincinnati, the Bengals had one top-10 defensive ranking in 18 seasons. Under Zimmer, the Bengals have had four in the past five seasons and reached the playoffs three straight years for the first time in franchise history.

Yet Zimmer was consistently passed over for head coaching jobs. One person close to him said it's probably because Zimmer is too frank, too unpolished and that, "he's made his mark as a football coach, not a smooth, slick CEO who walks in with his own PR firm."

Zimmer told reporters in Cincinnati two weeks ago that he's gotten better at interviewing since admittedly blowing one with the Rams years ago. He also said there were times when he knew immediately that the fit wasn't right.

"Once, I had to fill out like a 200 [question] questionnaire on like, 'If it's sunny out, do you feel …' " Zimmer said. "I didn't think that one was a real good fit."

Straight shooting

Zimmer has pulled few, if any, verbal punches on the job. The most famous one was directed at Bobby Petrino, who hired Zimmer away from the Cowboys to the Falcons in 2007, only to quit 13 games into the season to accept the head coaching job at the University of Arkansas.

"When a coach quits in the middle of the year and ruins a bunch of people's families and doesn't have enough guts to finish out the year, I'm not a part of it," Zimmer said then. "And you can put that in the Arkansas News Gazette. I don't really give a [expletive]. … He's a coward, he ruined a bunch of people's lives, a bunch of families, kids, because he didn't have enough [guts] to stay there and finish the job. And that's the truth."

Vikings players were fiercely loyal to Frazier, who also was regarded as an honest dealer with his players. With Zimmer, they'll get the honesty with different packaging.

"He's going to yell at you and try to get the best out of you,'' said defensive end Brian Robison. "But if you deserve praise, he's going to praise you up. I guess it's just a different change of pace from coach Frazier."