Joe Berger studied mechanical engineering at Michigan Tech. If you don't think that sounds like the surest path to a 13-year career in the NFL and a date in the NFC title game, you know nothing about mechanical engineering.

(Author's note: I know nothing about mechanical engineering.)

"I studied it because I liked the whole 'Taking a pile of whatever and making something out of it' thing,'' Berger said.

It's the time of the football season when the best metaphors just might be uttered by a 315-pound man with a 20-pound beard.

The Vikings offensive line, a pile of whatever last year, has become a driving force on a 14-victory team, and Berger, a sixth-round draft pick out of a small school in the Upper Peninsula, has made something of himself.

Sunday, Berger, the Vikings' 35-year-old offensive lineman, will play in what could be his last game, or the game that leads to his first Super Bowl. He has played 13 seasons for four teams, making two stops in Miami and considering retirement at least once.

"I'm pushing those thoughts aside right now, but in my mind, this is it,'' Berger said. "But I need time to figure out what I want to do.''

The Vikings will miss him dearly whenever he departs. He's Case Keenum with a hand on the ground, a journeyman who became a success story in Minnesota.

That's a testament to his gumption and versatility, but defining Berger with those backhanded adjectives misses a larger point: He has been an excellent player.

He was a dominant run-blocker in 2015 as a center, his position for most of his career. His play prompted the team to release a very good player in John Sullivan. This year, with the team drafting center Pat Elflein and desperate to fix an offensive line that ruined a promising 2016 season, Berger moved to guard.

So a walk-on at a small school drafted in the sixth round released by three different teams, including the Dolphins twice, who chose former Vikings draft bust Ryan Cook over him in 2011, became a standout at two different positions for a team desperately in need of quality line play.

The Vikings are lucky he didn't retire. He considered it in 2011, but his agent recommended visiting the Vikings, whose key front-office bosses had known him in Miami.

"I got released in Miami right before the season started,'' Berger said. "I thought, well, you had a six-year career, that's not terrible. But my agent was like, 'Go up to Minnesota and see what you think.' ''

The Vikings signed him as a backup. He became more than that. Now he's a powerhouse run-blocker, mild-mannered mentor and egoless veteran who doesn't mind playing any position.

"Year five of six of my career I was in Miami and Bill Parcells was the VP there, and he sat down with me at lunch and told me if I kept working like I was, I was going to have a 12-year career,'' Berger said. "I was like, 'Well, that would be cool,' but I wasn't sure I should buy it. Maybe he knew what he was talking about.''

Berger will enjoy at least one more trip to Philadelphia, where he learned about one of America's most passionate fan bases when he played for the Cowboys.

"You're on the Cowboys bus, it's a division game, and you go through all of the tailgaters,'' he said. "We came in on a high overpass over the tailgaters and you could see this one guy lean back and chuck something.

"It seemed like it was in the air for a full minute, and all of a sudden an egg just smashed into the window right next to us. The dude looked like he could have played quarterback for somebody. That image is still in my mind.''

Berger has played in one NFL playoff victory. If he and the Vikings win one more, Berger could play his last game in his home stadium in a Super Bowl.

That would be impressive career engineering.

Jim Souhan's podcast can be heard at MalePatternPodcasts.com. On Twitter: @SouhanStrib • jsouhan@startribune.com