Jonah Pirsig spends fall Saturdays using his 6-9, 320-pound body to shield the Gophers’ backfield from danger, ready to pulverize defensive ends and destroy their will.

With long hair hanging from his helmet and sweat pouring off his shaggy beard, the offensive tackle grunts and grinds play after play in the trenches.

But on a recent morning, that same huge force of nature came strolling into Edina Highlands Elementary, wearing a blue V-neck sweater, beige jeans and brown boat shoes.

Pirsig ducked beneath the entryway to Naddie Baker’s kindergarten class, hunched down onto a stoop and invited the children to bring a book. Soon, he was surrounded by wide-eyed 6-year-olds, hanging from every word he read in “Franklin’s Blanket.”

“You would think he’d be intimidating for them,” Baker said. “But the kids instantly liked him. He just has a very welcoming presence.”

Pursuing a degree in elementary education, Pirsig spent the fall semester in a fourth-grade classroom and two mornings per week during the spring semester with Baker’s kindergartners. He has two semesters remaining to complete his undergrad and plans to eventually spend a fifth year completing his master’s.

Both of Pirsig’s grandmothers were teachers in his hometown of Blue Earth, near the Iowa border. His mother taught for a short time, and his sister also studied education.

“I think teaching’s in my blood,” Pirsig said.

So is football, of course. Several high-profile coaches made their way to Blue Earth (pop. 3,000) to recruit Pirsig, who had offers from Auburn, Ohio State, Iowa, Wisconsin, Michigan and Michigan State.

When Pirsig committed to the Gophers in July 2011, before his senior year, it was one of Jerry Kill’s first recruiting triumphs at Minnesota.

Pirsig redshirted in 2012, played seven games as a freshman and 12 last year as a sophomore, with seven starts. Now a junior, Pirsig is entrenched as the starting right tackle.

Injuries have slowed his development. He had knee surgery in 2013 and minor wrist surgeries each of the past two winters. Now he’s fully healthy, which has accelerated his progress in the weight room.

“I feel the best that I have since I’ve been in college,” said Pirsig, who turned 22 in early May. “It’s kind of nice to be able to walk around there and not have to feel aches and pains.”

Kill still sees big on-field potential for Pirsig.

“He had a very good, productive [2014],” Kill said. “The weight room is critical for him. I think he’s got a chance to be an All-Big Ten guy.”

Pirsig said he might wait to do his final teaching practicum if he shows enough potential this fall for next year’s NFL draft.

“But if football doesn’t work out,” he said, “I’ll always have teaching to fall back on.”

Drawn toward the classroom

Pirsig realized he wanted to teach as a high school senior, when he took a community service class and got assigned to a fourth-grade classroom in Blue Earth.

“I didn’t have a major picked out, so it was kind of nice that it hit me,” he said. “I didn’t have to put much thought into it; I just knew.”

The kindergartners weren’t as sure about him in January, when he first showed up in Ms. Baker’s class.

“I was nervous,” student Ibrahim Yusuf said, smiling. “Because he was super tall. And strong.”

Pirsig quickly endeared himself, especially during recess.

“He taught me how to do the swings,” Yusuf said.

As Pirsig roamed the classroom, his head sometimes brushed against the art projects hanging from the ceiling. Then a tiny voice would say, “Jonah?” and he would bend down like a chopped oak to help open the Elmer’s Glue.

His Twitter handle is @Jonahlikesmath. That’s his favorite subject.

Addy Lampe had a problem to solve: 3 + blank = 12. Pirsig grabbed 12 small cubes, took away three and Lampe counted the rest. “Nine!” she said, giving a high-five, with her little hand quickly disappearing into Pirsig’s giant paw.

“They’re already doing first-grade stuff at this time of year,” Pirsig said. “It’s unbelievable how much they’ve grown in the time I’ve been here.”

Those rewarding moments will stick with Pirsig, no matter how he fares on the field next fall. On Nov. 7, for example, he’ll be at Ohio State, playing before 108,000 raucous fans, trying to keep All-America defensive end Joey Bosa from eating Gophers quarterback Mitch Leidner alive.

The Horseshoe — Ohio State’s imposing stadium — might make Pirsig miss Highland Elementary.

“This is definitely different,” Pirsig said, comparing teaching to football. “I love them both equally. But I’ve never walked out of here having a bad day.”