Peterson said the injury wouldn't affect Sunday night against the Green Bay Packers and he is listed as probable on the team's injury report. However, the bigger concern might be the blocking in front of him, and that isn't helped by the latest injury report.
Underrated in-line blocker Rhett Ellison hasn't practiced this week and has been ruled out of Sunday's game after suffering a knee injury early in the season and an ankle injury on Monday night.
"He's a pretty big loss. We count on Rhett in the run game quite a bit," head coach Leslie Frazier said. "To not have him, it definitely makes a difference with some of the things that we want to do, but that gives some other guys an opportunity to step up and do a good job as well. But he is a big part of our run offense."
While analysts look for reasons why the Vikings running game is struggling (compared to Peterson's flourish of a finish last year), one of the factors rarely considered is the absence of Ellison. He was inactive for two games after the knee injury, but he has played less than 8 percent of the offensive snaps after playing 24 percent last year.
But when he has been in, he is the most efficient player in the team's running game, according to one statistical analysis. No player has a higher differential in the run game as Ellison.
When he is in the game, the Vikings average 3.56 yards more per rush than when he hasn't been in. Granted, it's a small sample size, but he is an integral part of the Bill Musgrave's offense that features heavy use of two tight ends.
In the search for answers on the struggles of the Vikings running game, Frazier said it goes beyond the typical blame assessed to an offensive line.
"It's not just our offensive line, but our tight ends and our receivers. They're a big part of our run game as well and they've got to block a little bit better," Frazier said. "We have to stay on our blocks longer than what we are. We're having some (defenders) come off of blocks and making some plays. But when you run the ball the way we try to run the ball, it includes the tight ends, the wide receivers and even the fullback as well. It's not just the offensive line. All of them (need to) sustain our blocks and that's something we're working on this week."
Interestingly, Ellison also has the biggest passing differential on the team. They average 2.89 yards more per pass with him in the game.
Of course, Ellison isn't the only reason the running game is struggling. Peterson said the offense needs to play with more physicality.
"That's the MVP of the NFL so I'm going to take his advice," said left tackle Matt Kalil. "We're pretty tough on ourselves as critics, so I don't think anyone is going to give any harsher judgment than we do on ourselves. We know we have to be more physical and maintain our blocks and he can run with the ball and do what he does best."
The coaching staff isn't blameless, either and Frazier knows it. While the score of some games has gotten away from the Vikings early, like a 35-10 loss to the Carolina Panthers when Peterson had 10 carries, the coaches admittedly got away from the running game too soon in other contests.
The Giants game was a perfect example of that. The Vikings never trailed by more than four points in the first half, but Peterson had only eight carries. He finished with 13 carries.
Frazier has maintained all week that the coaching staff has to do a better job of sticking with the running game.
"It's something we've talked about. We're going to have some zero runs, some negative runs. We can't get away from it," he said. "We know how we're built and we know in order for us to be good we need to stay with it. We realize that. We need to be more patient with it for sure."
On Sunday, their patience may be tested. They won't have Ellison and they will be facing the NFL's third-ranked run defense.
"We still run some of the same plays (without Ellison) and we still want to be as effective as we were," Frazier said. "We may not go to the same spot, but they are the same plays. He definitely makes a difference for us."
Tim Yotter is the publisher of Viking Update. Follow Viking Update on Twitter and discuss this topic on our message boards. To become a subscriber to the Viking Update web site or magazine, click here.