MANKATO — As Mike Zimmer returned to the field with the Minnesota Vikings for the second half of their exhibition opener, the hard-nosed head coach was asked by a sideline radio reporter for some personal highlights from the first two quarters.

“There wasn’t much that I liked,” Zimmer said, “to be honest with you.”

The blunt style that contributed to being passed over for several head coach vacancies until the Vikings hired him in 2014 has not faded. The 3-8 finish for Minnesota after a 5-0 start last year, and the detached retina in Zimmer’s right eye that required eight surgeries in seven months, didn’t dampen his spirit for the job.

Beginning a crossroad season, Zimmer is as no-nonsense, persistent and uncompromising as ever. The unprecedented feat of playing in a Super Bowl on home turf will be a powerful motivator for the Vikings in 2017. Not that they need more of it.

“What I appreciate about Zim is, from Day One to today, he’s always been a straight shooter,” owner and president Mark Wilf said. “He tells it like it is, to his players, to his coaches, to the staff and to ownership. There’s a lot of accountability with him. He shoots straight with others, and he expects the same in return.”

Signs of an adjusted perspective have been easy to spot, though, in the dawn of this critical year in Minnesota.

Returning from his Kentucky vacation ranch, where he was sent for two weeks this spring to rest his eye, Zimmer appeared as upbeat as he had been in months. His doctor told him his retina was perfect, though mindful of the potential for future trouble with the left eye.

He spoke recently of learning “how to truly be a head coach” while referencing five-time champion Bill Belichick’s rough start in the profession before thriving with the New England Patriots.

“You’re just trying to put your fingers in different holes as much as you can,” Zimmer said. “It takes a while to learn how to do this job. It really does.”

His resume was built on 14 years as an NFL defensive coordinator, and to this point he’s been one of the rare head coaches in the league who’ve also called plays for the defense. Zimmer, however, has considered a transition plan for defensive coordinator George Edwards to be the lead caller during games. He’s confident enough, he said, in the development of the group under his direction to no longer feel the need to pick every play.

He has been spending more time with the offense, joining position meetings with the line and focusing more on managing in-game strategy while the Vikings have the ball. During his hiatus from spring practice, Zimmer sent nightly text messages to quarterback Sam Bradford to help him better understand the way defenses will attack him while forging a stronger bond with the eighth-year veteran along the way. Other players were recipients of similar electronic critiques from film of the workout earlier in the day.

“He is probably one the most upfront, honest coaches I have ever played for,” Bradford said. “I think that’s one of the things the guys really respect, because we know he’s in it with us.”

There have been hiccups, notably last season.

In the second-to-last game at Green Bay, cornerbacks Terence Newman and Xavier Rhodes, two of Zimmer’s closest pupils, strayed from the plan for covering wide receiver Jordy Nelson in a defeat to the Packers. Sloppy communication, including from Zimmer to the media afterward, was a culprit.

But coach-player disagreement factored in, a conflict that was one of many adverse developments during that injury-ravaged autumn. Zimmer was concerned enough about losing the trust of the locker room that he sought and received assurances from several players in offseason conversations that he had not.

So make no mistake: This son of a long-time high school coach, whose own son is Minnesota’s linebackers coach, is not about to go soft. His sensitive side was saved for his daughter’s wedding earlier this summer, not for the practice field.

“We’re going to get back to being the Vikings,” Zimmer said, “and we’re going to be blue collar and do things the way things that got us to be when we played teams that they respected the way that we played.”

That exhibition opener at Buffalo on Thursday provided a vintage picture of Zimmer and his demanding approach. By beating the Bills, the Vikings raised their preseason record under Zimmer to a robust 13-1. Such is at least trace evidence, as meaningless as the outcomes of these games in August are, of a team pushed hard to learn, work and prepare.

“My expectation for this team is a lot higher than that,” Zimmer said, “so we’ve got to get back to work.”