Mike Zimmer assigned homework Monday. Chances are his players took it seriously, even though there was nothing tangible for them to actually turn in.

By now, 26 games into Zimmer’s stint as Vikings head coach, players know that there’s more to “Zim” than old-school toughness wrapped in an unshaven, tobacco-dipping, between-the-eyes straight shooter. There’s also the cerebral side that, players say, demands as much attention mentally as the gruff side does physically.

This is cornerback Terence Newman’s seventh season of working for Zimmer. It’s also his third team, stretching from Dallas through Cincinnati.

One of the reasons players such as Newman still can start and play effectively on a 7-3 team at age 37 is physical talent. He was, after all, the fifth overall draft pick in 2003.

But there are other reasons for their long-term success. Reasons that have to do with football’s underappreciated intellectual side. Reasons that have to do with classroom work ethic, something Paul Brown introduced to the game decades ago when the Browns — yes, the Browns — were the league’s model franchise.

“I’ve never been a guy who falls asleep in meetings,” Newman said with a smile.

At 37, Vikings cornerback Terence Newman remains productive in his seventh season on a defense coached by Mike Zimmer.

The 13-year veteran was talking about his longevity a couple of weeks ago. He was asked what would chase him from the game first. The physical aches and pains from the field or the mental monotony and boredom from the classroom.

He said he won’t know until that day arrives, either by his choosing or by 32 NFL general managers choosing it for him. But then he went on to describe how the mental side isn’t always monotonous and how Zimmer helped him establish a sound base for the kind of film study and classroom attentiveness that would help him on the field.

“I was in Dallas with Zim as a rookie [2003] and played [four] years with him [as the defensive coordinator],” Newman said. “I remember we had some guys who would doze off or whatever in meetings. Zim would yell, ‘Hey! Stand up!’ ”

And those guys, some of them twice Zimmer’s size, would stand and remain that way through the meeting. Now that’s commanding a room.

“I didn’t want to have to stand up because it was funny watching guys so tired that their heads would start to doze,” Newman said. “You knew it was only a matter of time before you’d hear Zim and they’d be standing up.”

Generally, the league’s better players take the days between games as seriously as game day. They’re sharp enough to understand that preparation is one of the reasons they become one of the league’s better players.

After his time in Dallas, Newman found his way to Cincinnati (2012 and ’13) to be part of Zimmer’s defensive revival there. This year, he showed up in Minnesota, where, despite Sunday’s alleged End-of-Days loss to Green Bay, the Vikings still rank third in scoring defense (18.4 points allowed per game) behind New England (18.2) and Denver (18.3), and one spot ahead of Cincinnati (18.6), which still plays Zimmer’s scheme.

The difference here, of course, is Zimmer is the head coach. But he’s still a hands-on teacher, an X’s and O’s head coach who will run meetings. Players understand that they’ll need to, A, stay awake and, B, know their assignments because Zimmer will randomly call on them and ask questions to find out if they did their homework.

“I want them to watch some tape [Tuesday] on Atlanta,” Zimmer said Monday. “A lot of times, I’ll tell them to do that [on Tuesdays].”

Tuesdays are off days in the NFL. But film of the Falcons was no doubt rolling around Eden Prairie on Tuesday.

With a 30-13 loss to a rival still gnawing at the players on Monday, Zimmer felt like this was the perfect time to get a jump on the next opponent.

“When they come in Wednesday,” he said, “they better be smiling because it’s time to get going.”

Mark Craig mark.craig@startribune.com