For the Packers, that's been the trouble against the Minnesota Vikings' superstar this year.
In two games this year, the Packers have allowed Peterson 409 yards on the ground and two touchdowns.
Simply put, the Packers haven't stopped Peterson. They almost single-handedly helped him break Eric Dickerson's single-season rushing record.
And it's not as if they don't know the ball is going to go to him.
With a second-year quarterback who is still struggling to make good throws at the pro level, the Vikings have to lean heavily on Peterson. The Vikings know that, the Packers know that and the fans know that.
But they still can't bring him down.
When teams have a running quarterback, defenses usually stick a spy on him just in case he comes out of the backfield. For the Packers, they need to employ this same philosophy.
By having someone like Clay Matthews focus on Peterson, and Peterson only, the Packers are going to make Christian Ponder beat them.
Sure, it takes your best linebacker out of most equation. But, it also will limit Peterson (in a sense), forcing Ponder to find his receivers downfield.
So, what are some other keys to the Packers pulling out the win?
Throw the Ball a Lot
Telling quarterback Aaron Rodgers to throw the ball a lot is not rocket science. He's one of the best quarterbacks in the NFL.
Minnesota ranks 24th in the NFL in passing yards allowed per game (244.3).
Rodgers has thrown for 651 yards and five touchdowns in two games against Minnesota. He's finding open receivers and has utilized all of them.
James Jones has been one of the more dependable guys on offense as he's found the end zone 14 times on passes from Rodgers.
Slow Down Jared Allen
Allen has a motor on him like none other when it comes to the defensive front. The Packers have to figure out a way to slow down that motor.
The nine-year veteran has three sacks on the year against the Packers.
By stopping Allen up front, it could allow for more success in the running game and give Rodgers more time in the pocket.
Let's be honest, Brian Robison isn't going to bring that same kind of consistent pressure from the other side. Neither is Kevin Williams or Letroy Guion in the middle.
For Minnesota to have any success along the defensive front, it has to start with Allen.
Was Adrian Peterson Mentioned?
In case the theme of this story has been missed, the Packers must stop Peterson.
There's no two ways about it. If Green Bay allows Peterson to run all over them like he did in Week 17, the Packers will find themselves staying at home in the next round.
Peterson is the best player in the NFL and has been showing this all season.
No other player on the Vikings is going to beat Green Bay. Peterson is the guy the focus should be on.