METAIRIE, La. -- Brian Dobie was sitting in his office in September 2011 when the University of Manitoba football coach heard a "soft knock on the door."

In walked a 6-foot-4, 330-pound kid he had never seen before.

"There was this guy that I hoped would be a football player standing at my door," Dobie recalled.

He got his wish. Sort of.

That kid was David Onyemata, who had just moved from Lagos, Nigeria, to Canada earlier that year to attend the university. Though Onyemata played soccer growing up in Nigeria, he had never really even heard of North American football before he moved to Canada.

Onyemata moved to Canada to study environmental sciences. But after a few months in his new home, Onyemata decided he needed a hobby.

"I just felt it was time to give something a try, because all I did was go to class and go back home. I had so much free time," Onyemata said. "So I ended up just trying out for the team."

Five years later, Onyemata is now a member of the New Orleans Saints after they traded up to draft him in the fourth round on Saturday.

"It's a pretty great story. Up here in Canada, we're literally calling it Cinderella," said Dobie, who recalled that Onyemata had never even held a football in his hands until that day they met in his office.

"He made a comment that it kind of looked like a rugby ball," Dobie said. "In his first year, he was so beyond ground zero raw. He didn't know a stance. He didn't know the rules of the game. He didn't know anything."

But the talent was obvious.

Dobie said the first time he and his defensive coordinator, Stan Pierre, took Onyemata onto the field and saw him move, "We were shocked."

"(Pierre) turned to me and, I remember this vividly, said, ‘Shame on us if we can't turn this kid into a football player,'" Dobie said. "He was just a football player waiting to happen."

The Saints felt the same way.

When general manager Mickey Loomis was asked if there was someone who really "stood on the table" and made a plea for Onyemata, Loomis said, "Everyone."

"Beginning with our area scout and following all the way through (assistant coaches Bill Johnson and Brian Young) and everyone that looked at him," Loomis said. "I would say that everyone was standing up saying, ‘This is a guy that we want.'"

Johnson was one of only two defensive-line coaches who attended Onyemata's pro day at Manitoba -- but Onyemata was hardly an NFL secret. A total of 17 teams were represented at that pro day, which Dobie said was by far the largest in Canada's history.

One of Onyemata's agents, Don Yee, said he took an estimated 19 pre-draft visits, which was the most of any player he's ever had.

Onyemata was generating more and more buzz leading up to the draft, and Loomis said the Saints were confident that he would have been gone if they waited until the fifth round to select him.

"We recognized that he wasn't playing at a SEC school, obviously, so there are some questions about the level of competition. But, man, we like the traits and the talent," Loomis said. "And we're expecting some early contribution from him. This isn't a guy that's just going to sit and not be productive for us."

Onyemata is the first player ever drafted from the University of Manitoba. The Bisons also produced DE Israel Idonije, another Nigerian-born player who spent 11 years in the NFL.

He is the 12th Canadian college player ever drafted into the NFL -- a list that also includes former Saints DT Akiem Hicks from the University of Regina in 2012.

Yee, who also represents Saints coach Sean Payton, said Onyemata reminds him of a former client, Hall of Fame guard Larry Allen, who went from a small school to the Dallas Cowboys.

"He has a natural, powerful explosion," Yee said. "Larry had a tremendous natural explosion. David's body reminds me of Larry to a degree."

Onyemata, now 6-foot-4 and 300 pounds, had 50 tackles, five sacks, 7.5 tackles for loss, a forced fumble and a fumble recovery in nine games last year. His measurables were impressive at his pro day -- including 33 reps in the 225-pound bench press, which would have tied for the most among all defensive linemen at the NFL combine. He also had a 33-inch vertical leap.

Payton said he sees Onyemata as a defensive tackle in sub packages and possibly as a defensive end in base packages.

John Murphy, a Metairie-based scout who has spent years working as a personnel executive in the Canadian Football League, said he could see Onyemata being even better than Idonije, who had an impressive career with 29 total sacks.

One of the big adjustments he'll have to make is lining up directly over the offense, since they have a 1-yard cushion in Canadian football.

"He was graded as the top player for the upcoming CFL draft, shows impressive quickness and pursuit skills for a 300-pound defender, showed up big at the East-West Shrine Game," said Murphy, an assistant vice president for the Saskatchewan Roughriders who called him a "worthwhile" pick in Round 4. "If you're trying to rebuild on that side of the ball, you need to take some risks in order to find and develop playmakers."

If Onyemata continues to develop as rapidly as he did at Manitoba, that risk will pay off.

That first year at Manitoba, he spent most of the season working one-on-one with a defensive lineman who was sidelined by an injury. But Dobie said he bought in quickly, and he loves to learn.

"I fell in love with the game. That's what happened. I enjoyed hitting guys, just being out there with the guys. I'd love to do this for a long time," said Onyemata, who wound up in Canada because his older sister had also gone to Canada to attend school and his parents were happy with it.

Dobie laughed at just how foreign the idea of the NFL draft is back in Nigeria. He said that when Onyemata would call his parents and tell them about his pre-draft visits with various NFL teams, he said his parents "just worried, is someone gonna pick me up at the airport? Do I have a place to stay?"

Onyemata is extremely humble, Dobie said, which is one of the reasons why the longtime coach couldn't stop tearing up Saturday and why the rest of the team exploded when they heard the news after practice and took turns pouncing on Onyemata with hugs.

"He's the most respected player in our locker room for obvious reasons," Dobie said. "But the true reason he's so respected is who he is."