MANKATO, Minn. -- George Stewart would pass by Scott Turner's office, or the Minnesota Vikings wide receivers coach would see the quarterbacks coach at a college all-star game, and the refrain was always the same.

"Scott came up as early as January -- 'Hey Stew, you've got to look at this Diggs guy. You've got to look at this Diggs guy,'" Stewart recalled this week. "It got to a point [where I said], 'I know, Scott, it's got to be the Diggs guy.'"

Turner was the wide receivers coach at the University of Pittsburgh in 2011, competing with programs bigger than his to woo Stefon Diggs away from the University of Maryland. The Gaithersburg, Maryland, native was the 13th-best recruit in the country, and even through Pittsburgh's unsuccessful pursuit, Diggs' bona fides -- his subtle head fakes, the way he changed directions like a motorcycle banking through a chicane -- were burned into Turner's mind.

Three injury-filled years at Maryland, and the decision to leave school a year early, muddied the outlook on Diggs for some, but Turner kept reaching to the memory he had of the player in high school. And with the 146th pick in the draft this year, the Vikings picked a player on whom they're already willing to heap lofty expectations.

"He's very similar to Percy Harvin when Percy came out," Stewart said. "Same type of athlete, but more athletic."

More athletic than Harvin -- the player who overshadowed Adrian Peterson as an MVP candidate in the first half of 2012?

"More athletic," Stewart repeats for emphasis.

Though Diggs has fashioned a striking start to training camp, the rookie almost seems less impressed with himself than anyone else. Asked about his two touchdown catches in front of 10,000 fans during the Vikings' night practice last Saturday, Diggs shrugged and pointed out the pass he dropped. When the Vikings called to tell him they were selecting him in May, Diggs was watching film of himself at Maryland, not draft coverage. His wide receivers coach at Maryland was Keenan McCardell, a former 12th-round pick who caught 883 passes in 16 NFL seasons and served as a constant reminder to Diggs that he wouldn't succeed in the NFL on prodigious talent alone.

"He loves football," Stewart said. "The first night he came on our campus, someone told me -- I don't know if this is true or not -- they were leaving the back parking lot. It was dark. They were putting their lights on to leave. He's out there in a helmet and a jersey, running routes on his own. I didn't want to go and embarrass him [by asking him about it]. If that's what he's doing, I want him to be a gym rat."

At this point, the stories about Diggs seem to have as much to do with his tenacity as anything else. He got hit from behind while trying to stretch across the goal line against Penn State last November, and played the rest of the game without giving much thought to the pain. After the game, Diggs realized the injury was more serious. "Anybody who's familiar with kidneys, what happens when you use the bathroom, I was like, 'Ah, something's wrong.'"

It turned out Diggs had lacerated a kidney. He was already ineligible to play the next week, thanks to his role in a pregame altercation with Penn State, but the injury ended his season and his college career. Still, it showed the Vikings how much Diggs loved football and what he'd endure to stay on the field.

That hasn't changed since Diggs joined the Vikings and linked up with a handful of receivers who are typically the last ones off the practice field. Mike Wallace and Charles Johnson routinely stay for another 20 minutes after practice, catching balls from a Juggs machine. When one wasn't available after a Tuesday night practice, some of the receivers ran sprints instead.

"They love me," Wallace joked about the young receivers. "We have a great group of guys, hard-working guys, everybody willing to learn, everybody willing to help each other."

The Vikings thought they were getting a veteran role model when they signed Greg Jennings two years ago, but Jennings never seemed to click with the other wideouts the same way Wallace has.

"We've never had that true veteran guy here," Stewart said. "Greg was trying to do it, but we've never had that true guy who's like Mike Wallace. You remember that old commercial -- 'When E.F. Hutton speaks, people listen?' That's Mike Wallace. He's not afraid to get into your face."

In Diggs, the Vikings seem to have a rookie who's equal to the task. If they're unafraid to speak so highly of him so soon it's because they believe he'll work hard enough to realize their expectations.

"He's nowhere near saying he's ready for the Hall of Fame yet. He's got a long ways to go," Stewart said. "But he's working every day."