Darrell Thompson attended Rochester John Marshall High School, then played football for the University of Minnesota.

Marcus Sherels also attended John Marshall and played for the Gophers.

Thompson was a big, strong, fast, smart athlete who became a college star. The Green Bay Packers drafted him in the first round in 1990.

Sherels was an undersized walk-on at Minnesota who earned a scholarship and became a quality college player. He went undrafted.

Thompson lasted five years in the NFL. Sherels is about to pass him in pro football longevity.

Sherels signed with the Vikings as an undrafted free agent in 2010. He has spent his entire NFL at the bottom of the roster, knowing he could be released at any moment. At a listed 5-10 and 175 pounds, he has become an effective punt returner and willing utility player.

When the Vikings re-signed him last week, Sherels was set up to play a sixth season in the NFL.

As Sherels' mentor, Thompson is not surprised.

He sees one physical and one emotional reason for Sherels' longevity.

The physical: "I noticed at Minnesota that he had the ability to close," Thompson said. "Closing speed is hard to describe, but he had the ability to accelerate when most people don't."

The emotional: "As a mentor, you're there for everything,'' Thompson said. "If he had life problems, or lady troubles or academic problems, I was there for him. Marcus actually had none of those. I had other athletes that were or are troubled. Not Marcus."

Thompson had a friend who worked on the Vikings coaching staff. The coach invented a test for defensive backs. The cerebral Antoine Winfield registered one of the highest scores, in the high 90s.

"Marcus made a perfect score," Thompson said. "I don't know if people understand how important that kind of intelligence is. In the NFL, coaches are only going to tell you something so many times. They're not going to keep correcting you. You tell Marcus something one time, and he's got it. He'll line up in the right place and understand the situation. That's not as common as you might think."

Thompson himself often wondered whether there was another side to Sherels than the stoic who dedicated himself to a game that could have done without him. He asked the then-girlfriend, now-wife of Marcus' brother, Mike, a standout linebacker for the Gophers, whether Marcus might be occasionally sneaking out to party.

"I asked her, 'Is he just telling me all this, or is he really this perfect?' " Thompson said. "She said, 'He lives in our basement and makes up math games. He is who he is.' "

Thompson is an analyst on Gophers football broadcasts. He also is the president of Bolder Options, a mentoring program described on the company website as "an innovative organization focused on healthy youth development."

Thompson has been mentoring young people for a long time. He considers Sherels one of his easiest assignments.

"I'm proud of him," Thompson said. "I think he's doing great. He's a great person. He's the epitome of what happens when you work hard, really bust your butt.

"With the right attitude and work ethic, you can achieve great things. And he is."

Jim Souhan's podcast can be heard at MalePatternPodcasts.com. On Twitter: @SouhanStrib. jsouhan@startribune.com