"He might be me, I don't know," Cook said, laughing. "I try to give Deuce as many tips and everything I can. He sees the field how I see the field. It's crazy when we come off the field how we see things so similar. He's just a bigger version. When he comes in, he's trying to break the home run, too.
"I do think Deuce is a similar version of me."
"Deuce," the nickname Cook bestowed on his No.2, has a chance to start his first NFL game Sunday when the Vikings play host the Atlanta Falcons (1 p.m. ET Sunday, Fox) ahead of their Week 7 bye. In the midst of the best three-game rushing stretch of his career (376 yards from Weeks 3-5), Cook sustained a groin injury on the Vikings' opening drive in the third quarter at Seattle. Cook returned for one play to determine whether he could work through it before Mattison took over, finishing with a career-high 112 yards on 20 carries.
Cook didn't practice Wednesday and things are trending toward him taking two weeks to rest before the Vikings open the second half of their season at the Green Bay Packers on Nov. 1.
"You kind of have to let your body naturally heal," Cook said. "I'm in year four, I kind of know how this thing pretty much operates. I'm going to get as much treatment as I can, I'm going to stay on my same routine, nothing's going to change. On the play, I have turned on that same screen play 100 times and it was just a freak accident. It's part of football. I'm going to stay committed to what I do, and I'm going to see what's the outcome of it come Sunday."
According to Zimmer, the Vikings weren't looking for a player who fits the Cook mold when they selected Mattison in the third round of the 2019 draft. But it's obvious Minnesota wants a certain type of rusher to fill that No. 2 role.
Latavius Murray, Cook's backup from 2017-18, is a big, imposing back who can spark a downhill rushing attack. At 5-foot-11, 220 pounds, Mattison is the same way. Having a physical runner behind Cook has been Minnesota's priority, and Mattison's skill set means the Vikings don't have to change their approach if he's in the game.
"I don't feel there's a lot of limitation there in terms of an area of the offense," Vikings quarterback Kirk Cousins said. "[Mattison] can obviously run the ball, he can pass protect, he can catch the football, he can run all the routes. He knows the game plans inside and out so you are able to run your offense. And the same can be said of Mike Boone and Ameer Abdullah. So having depth there is a great help."
Added Zimmer: "They're a little bit different styles sometimes, but [Mattison] runs hard, hits the holes good and has been good in protection."
The Vikings spent Weeks 1-5 working through a plan to spell Cook. In the moments they've turned to Mattison, Minnesota has been able to spark a screen game (three catches for 24 yards in Seattle) and keep its foot on the gas with the run (99 second-half yards from Mattison against the Seahawks).
"As a running back, the more touches you get, the more you can get in a rhythm, so it's awesome to have the experience. But now we'll take that into this week as we go on to get Atlanta," Mattison said.
Mattison is averaging almost five yards per carry in his first five games coming off a rookie season in which he had 544 yards on 110 touches. He's played a significant role in the Vikings establishing the NFL's fourth-best rushing offense (160.6 yards per game).
"When they brought him in, I think that was the greatest thing they did," Cook said. "We push each other, we're happy for each other. When it's time for me get on him, I get on him. When it's time for him to get on me, he gets on me. It's vice versa for both aspects."