While coaching with the Washington Redskins from 2010-11, two-time Pro Bowler Keenan McCardell heard whispers of a talented high school prospect in the Maryland area named Stefon Diggs.

It wouldn’t be long until Diggs was McCardell’s protege at the University of Maryland in 2014.

McCardell, now the Jacksonville Jaguars receivers coach, was at TCO Performance Center Thursday for his team’s joint practices with the Minnesota Vikings. He spoke to Zone Coverage about his year as Diggs’ receivers coach.

“He’s one of the most competitive dudes I’ve ever been around,” said McCardell, “besides myself.”

McCardell played 17 years in the NFL, amassed over 10,000 receiving yards and two Super Bowl rings. He and Diggs are similar. Both are on the smaller side — just a shade over six feet and 190 pounds. Both were also overlooked. The NFL Draft was longer in 1991, and McCardell had to wait until the 12th round, where he was the 326th overall pick.

Diggs’ wait lasted until Pick 146 in the fifth round in 2015.

When McCardell got to know Diggs at Maryland, he saw a player with immense potential. Diggs had averaged over 700 yards in his first two seasons with the Terrapins, but McCardell wanted to unlock more.

“Great talent,” said McCardell, “but needed to develop a work ethic, the type of work ethic to match his competitiveness.

“I pushed, I pushed, I pushed and pushed. Anytime he would run a play 50 yards, ‘Come back, let’s go, you’ve got to go again.’ He’s like, ‘Coach, I just’ — ‘Nah, I don’t want to hear it. Shut up. Get in the huddle. You’ve got to go do it again.'”

Work ethic has never been an issue for Diggs in Minnesota. The fourth-year pro regularly stayed late after practice to get extra reps early in his career, quarterback Kirk Cousins has talked about his attentiveness in meetings and after Diggs’ miraculous game-winning touchdown against the Saints last year, he coyly said he had squats scheduled for the next morning.

McCardell drilled home to Diggs that being an NFL receiver required an insatiable energy level.

“I keep telling him it’s like this: If you’re Michael Jordan, but you’re dead tired, but you’re hot, do you want to come off the court or do you want to stay on the court?

“As a receiver, when you’re hot you’ve got to be like a jump shooter or a scorer. Keep me on the court or keep me on the field and keep feeding me. That’s the type of mentality I wanted him to establish.”

Diggs notched four 100-yard games his junior season at Maryland, including a season-high 10 catches, 138 yards in the Terrapins bowl game against Stanford. Diggs opted to go pro after that performance, foregoing his senior season. McCardell became his biggest advocate, vouching to teams that Diggs had 4.4 speed and was terrific after the catch.

The Maryland product entered the NFL as a ready-made route runner. After his second game, Mike Zimmer declared his route-running “excellent.”

Before that 2015 season began, Zone Coverage spoke with Diggs, who said he loved imitating other elite receivers. “Every good receiver, I watch them on tape, watch everything that he does that’s good,” Diggs said at the time, “and whatever I’m doing that’s bad he can help me with that. I watch everything.”

This was a tip straight from McCardell.

“I wanted him to understand what was going to happen at the next level and put it in his game,” McCardell said. “I would say, ‘Put it in your bag of tricks.’ Always gotta look at different guys. I told him this all the time. You look at different guys to steal from somebody else. If the other guy’s doing it, you might as well try it, and if you can do it too, it can work for you also.”

Minnesota recently signed Diggs to a lucrative five-year extension, giving him a home through 2023. McCardell, who had to wait until his fifth NFL season to truly emerge, is thrilled for his former pupil.

“Sometimes the man upstairs puts you in the right spot at the right time in the right situation, and coming to Minnesota was the right situation for him,” he said. “He’s been rewarded with it because of his play, he’s been a leader, he’s been their playmaker.”