EAGAN, Minn. — A week ago, ESPN ranked Dalvin Cook and Alexander Mattison as the NFL's top running back tandem.

There was plenty of evidence to support that honor, as the Vikings rank fourth in the NFL with 160.6 rushing yards per game. And in five games this season, Cook has a pair of 100-yard rushing performances, and Mattison just carded the first of his career.

But with Cook dealing with a groin injury that could keep him out of Sunday's game against the Falcons, the spotlight could shift to Mattison in Week 6.

"Alexander is a good back, a really conscientious kid," Vikings Head Coach Mike Zimmer said Wednesday. "He works real hard and tries to learn from Dalvin as much as he can.

"They're a little bit different styles, sometimes, but [Mattison] runs hard, hits the holes good and has been good in protection," Zimmer added.

Mattison, who noted he hopes Cook will play, said: "We're going to … prepare to go out there and get after it — both of us and the entire running back group. [We're] taking this week the same as any other week. After last game, it was unfortunate that he couldn't finish the game, but fully expecting that we both go out there and get after it this week."

Cook was injured on Minnesota's first play from scrimmage in the second half against Seattle while running a route. He played one snap on the next possession, but the running back said didn't feel like himself.

The NFL's leading rusher with 489 yards and seven rushing touchdowns, Cook underwent an MRI on Monday. He offered an assessment of his health on Wednesday morning.

"I feel better. Still taking this thing day-by-day," Cook said. "As far as my Atlanta status, we're going to take this thing day-by-day. Just see how it feels after treatment and everything. It's day-by-day for me."

Added Zimmer: "I talked to him today, and he said he's feeling really good. So, we'll see how it goes."

Mattison shined in Cook's absence, churning out 112 yards on 20 carries as he recorded career bests in both categories.

The Vikings especially relied on Mattison in the fourth quarter, when he churned out 80 yards on 12 attempts, including a pair of runs went for at least 20 yards.

"Obviously it's something that you, as a running back, the more touches you get, the more you can get in a rhythm," Mattison said. "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 fared well as a rookie in 2019, running for 462 yards and a score on exactly 100 carries (4.62 yards per carry). He's been even better so far in 2020, with 219 yards and a score on 44 attempts, with an average of 5.0 yards per attempt.

The 22-year-old was a third-round pick in 2019 out of Boise State, where he rushed for 2,829 yards and 33 touchdowns for the Broncos.

At the time, the Vikings were searching for running back depth after Latavius Murray went to the Saints as a free agent. Zimmer said the Vikings were more than happy to select Mattison with the 102nd overall pick.

"We just knew we needed another back," Zimmer said. "I think at that time we were losing Murray, who was a really good back.

"We had a group of guys we liked there [in the draft], and Alexander was at the top of the list," Zimmer added.

Mattison's contributions as a rookie helped the Vikings rank sixth in the league in rushing at 133.3 yards per game.

And now that Mattison is a little more seasoned, his teammates don't expect any drop-off if he makes his first career start in place of Cook.

"Alex is a great back. I don't feel there's a lot of limitation there in terms of an area of the offense," said Vikings quarterback Kirk Cousins. "He 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," Cousins added. "So, having depth there is a great help."

Cook said that if he doesn't play against the Falcons, then he'll be right there to help Mattison and the rest of the running backs try to get a win, the same as he does during the week.

"I try to give Deuce [Mattison's nickname] as many tips and everything I can," Cook said. "He sees the field how I see the field, and 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," Cook added. "But he knows what's ahead of him. I do think Deuce is a similar version of me."

Said Mattison: "I don't like to say that I'm too much bigger than him, but I'll take the compliment, but we're both that two-headed monster."