Drew Petzing is right. He doesn't look like an NFL coach.

"I list myself at 5-8," he says, "but if I'm being honest, that's a little generous."

At 5-7, he looks to weigh about a buck-fifty.

"I wish," he laughs. "More like 170."

Yes, but Petzing's career path to Vikings receivers coach is a classic tale of just how big an NFL-sized work ethic is and how far it can carry someone this passionate about coaching football.

Told that his is an NFL story that gets lost in the shadows of big-name head coaches, $84 million quarterbacks and persistent Division II receivers from Mankato, the 32-year-old Petzing laughs again.

"Well," he said, "guys like me are a lot easier to find than those other ones you mention."

In 2005, all Petzing wanted to be was a Division III defensive back. The Wellesley, Mass., native was good enough to land at Middlebury College in Vermont.

Healthy enough? Not so much.

"I had a Lisfranc fracture and had a screw put in my left foot my freshman year," he said. "I came back from that but blew out my knee."

Playing career over. College games played: Zero.

But his first unpaid coaching job began as student volunteer while earning a major in economics and a minor in math and philosophy.

"I knew I wanted to coach, but I didn't know what the process was," he said. "So I just started calling everybody I knew."

Ben Bloom, now the linebackers coach for the Dallas Cowboys, is a family friend from Wellesley. At the time, he was assistant defensive line coach at Harvard.

"Ben said they were looking for an intern," Petzing said. "But it wouldn't pay."

But it was a good foot-in-the-door opportunity.

Petzing got the job. His parents, Larry and Leslie, got another mouth to feed.

"Food paid for, rent-free," Petzing said. "And Harvard is 20 minutes from my house."

The next two years were spent as a graduate assistant at Boston College.

"Even better," he said. "Only 15 minutes from my house."

Next up: Yale.

"Tony Reno, a guy I worked with at Harvard, got the head coaching job at Yale," Petzing said. "He called and asked me to coach a position [linebackers]. I jumped. And I had no intention of leaving."

A year later, in 2013, Petzing left for Cleveland.

Bloom and another former Harvard coach, Dave Borgonzi, now the linebackers coach with the Colts, were coaching interns in Dallas. When the Browns called Dallas looking for tips on setting up a similar coaching internship under first-year coach Rob Chudzinski, Bloom and Borgonzi recommended Petzing.

"Ben had gone to Cleveland earlier as an intern in what they called a '20-for-20 guy,' " Petzing said.

A what?

"Work 20 hours a day for 20 grand a year," Petzing said. "I took a pay cut coming from Yale."

Petzing helped Browns defensive coordinator Ray Horton put his playbook together. He helped in every position room in the building. He helped run the scout team. And when a player got cut or signed, Petzing drove them to or from the airport.

"The day would start at 6 a.m.," he said. "And I wouldn't leave until the building was empty. It was a great opportunity."

And one that led to Minnesota a year later when Chud's staff was fired and Norv Turner was hired as Vikings offensive coordinator.

Norv didn't have a specific title in mind. He just wanted his "20-for-20" guy.

"But," Petzing said, "the Vikings did give me a raise."

For two years, Petzing was a "coaching assistant." From 2016-17, he was assistant receivers coach to Darrell Hazell.

Before last season, Carolina and Indianapolis tried to hire Petzing. The Panthers, with Turner as offensive coordinator, wanted him as an assistant receivers coach. The Colts wanted him as receivers coach.

The Vikings denied both interview requests and moved Petzing to assistant quarterbacks coach under Kevin Stefanski, who is now the offensive coordinator.

When Hazell's contract expired, Petzing was promoted. His top two players are Adam Thielen and Stefon Diggs, the league's most productive receiving tandem.

"You can look at me and probably tell I didn't play," Petzing joked. "It's definitely a big thing."

But one he's outworked.

"Even the [most skeptical] players, if they think you know what you're talking about and have something that can help them, more often than not they're all ears," Petzing said. "That was important early in my career and is going to continue to be important as I hopefully move up in this industry."

Mark Craig is an NFL and Vikings Insider. Twitter: @markcraigNFL. E-mail: mcraig@startribune.com