Five years ago, a soft knock at his office door interrupted Brian Dobie’s phone conversation.

The University of Manitoba football coach turned to his left and immediately forgot about the phone call. A massive young man loomed in his doorway like an eclipse, a man Dobie instantly found himself hoping was a prospect he’d never met.

David Onyemata was not a football player at the time. But he wanted to be.

“Not only wasn’t he a football player, he’d literally never held a football in his hand,” Dobie said. “The first time he ever did that was in my office. I handed a football to him, and he made a comment that it looked a little like a rugby ball.”

Onyemata grew up in Lagos, Nigeria. Following in his sister’s footsteps, he moved to Canada to go to college. After a couple of weeks of classes, Onyemata found himself desperate for a little more action.

“I just felt it was time I try something,” he said. “All I did was go to school and go back home. I had so much free time that I needed to do something.”

Football, a sport Onyemata knew a little about from talking to high school classmates who had grown up in America, piqued his interest.

Dobie took Onyemata down to Manitoba’s kinesiology lab, measured the man-mountain at 6-foot-4 and around 330 pounds, and then took him out to the football field with defensive coordinator Stan Pierre to see what kind of athlete had dropped into their laps. Onyemata started moving, and Pierre turned to Dobie in disbelief.

“Shame on us if we can’t turn this kid into a football player.”

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Onyemata knew so little about the sport that he spent his entire freshman year practicing away from the rest of the Bisons. Every day, Onyemata went through individual drills to start practice, then moved off to the side to work with injured defensive lineman R.J. Skinner, who was charged with teaching Onyemata everything from how to take a stance to the rules of the sport.

By his second year, he was capable of contributing in a rotation, and Onyemata has been on a meteoric rise ever since.

“In 2014, I really felt comfortable with everything I was doing,” Onyemata said. “That was the first time.”

Onyemata grew into one of the best players in Canada. Double-teamed through most of his senior year at Manitoba, a slimmed-down, streamlined Onyemata had 38.5 tackles, 7.5 tackles for loss and five sacks in 2015 to earn the J.P. Metras Trophy, the award annually given to the top down lineman in Canadian Interuniversity Sport, Canada’s version of the NCAA.

But he still harbored little hope of playing in the NFL.

Few CIS players ever get the chance. Only three — including former Saints defensive end Akiem Hicks — have been selected in the NFL draft in the past seven years, and although Dobie’s Manitoba program has become a CIS power, his program usually produces CFL players. No Bison had ever been drafted, although former defensive end Israel Idonije, another Lagos native who started playing football late in life, spent 11 seasons in the NFL, mostly with the Chicago Bears.

“I’d only played one year of high school football — 9-man football,” Idonije said. “What he’s doing, coming off the street and never knowing football, is crazy. At least I’d watched football games; I came to Canada when I was 4 years old.”

Back in January, Onmeyata figured it was a long shot for him to match Idonije’s story.

“Four months ago, I was just getting an opportunity to play and maybe get the opportunity to try out for a team or something,” Onyemata said. “That is what I wanted out of it.”

Then Onyemata was one of three CIS players invited to the East-West Shrine Game, one of the annual senior showcases that kicks off the NFL draft cycle.

“It was just an opportunity to go out there and perform with the best going into the draft,” Onyemata said. “It was really huge for me.”

Onyemata held his own throughout the week of practices in St. Petersburg, Florida, then produced a sack in the game itself. Two days later, calls started flooding into Dobie’s office. NFL scouts hoped Onyemata had earned himself an invite to the NFL combine, but none came, and NFL rules kept the Canadian product from participating in pro days at Minnesota and Northwestern, according to SportsNet.

Without any other options, Dobie decided to hold Manitoba’s first pro day.

“It was the first real, true pro day — certainly the largest pro day — in the history of our country,” Dobie said. “There’s been some pro days up here, here and there, smattered across the country, very rarely. In those pro days, there’s been three or four teams. We had two-thirds of the NFL up here.”

Two defensive line coaches showed up among the gaggle of scouts that flooded into Winnipeg to see a 300-pound Onyemata run the 40-yard dash in 5.06 seconds, leap 9 feet, 11 inches in the broad jump and punch out 33 repetitions on the bench press, a number that would have tied for first at the combine.

One of those coaches was Saints assistant Bill Johnson.

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From the moment he met Johnson, Dobie had a feeling the Saints were one of four teams — along with the Patriots, Eagles and Lions — that might pick Onyemata. Dobie hoped his defensive tackle might slip into the third round, but he was guessing Onyemata would come off the board in the fourth — the fifth at the latest. When the Saints traded their third- and fourth-rounders to New England on Friday night to move up and take Ohio State safety Vonn Bell, New Orleans seemed like a long shot.

But then the Saints made another move. With Onyemata on the board, New Orleans traded its fifth-round pick and a fifth-rounder in 2017 to move up and take Onyemata in the fourth round, with the 120th pick.

Onyemata was on a golf course when he got the call.

“It was my first time golfing,” he said. “It was kind of a struggle early, but once I got that phone call, I started hitting the ball really good.”

Dobie got the call on the practice field.

“We’re in back-to-back practices of spring camp,” Dobie said. “At the end of practice, I brought everybody in, 135 guys on the field, and when I announced it, I teared up. You’ve got to understand, this isn’t Ohio State. ... When I announced it to our team, it was an explosion.”

Onyemata has a long learning curve ahead of him.

Beyond his lack of experience, Onyemata has to adjust to a different set of rules. In Canada, defensive linemen are required to line up a yard off the line of scrimmage, so Onyemata will have to get used to everything happening much faster.

But the Saints believe they’ve found a versatile prospect to help the defensive line. New Orleans envisions Onyemata contributing as an interior rusher initially, playing the three-technique tackle position and potentially moving out to play defensive end on running downs.

“We were really intrigued with his talent,” general manager Mickey Loomis said. “We recognized that he wasn’t playing at an SEC school, obviously, but man, we like the traits, we like the talent, we like the makeup of the player. ... I’m pretty confident — we had some information — that he wouldn’t have been available to us if we stayed right where we were at.”

Onyemata’s story is remarkable. Five years ago, when he moved to Canada, Onyemata had never seen a football game.

Now the sport is his shot at stardom.

“I just fell in love with the game, hitting guys and just being out there with my guys,” Onyemata said. “I’d love to do this for a long time.”

The Saints have given him the chance.