CHARLOTTE, N.C. (AP) -- The Panthers don't seem all that worried about who'll be playing quarterback for the Minnesota Vikings on Sunday.
Their focus this week is on stopping Pro Bowl running back Adrian Peterson.
Peterson, who ran for 2,097 yards last season, is second in the NFL in rushing this year with 421 yards for the Vikings (1-3).
It should be a huge test for middle linebacker Luke Kuechly and the Panthers (1-3), who are seventh in the league against the run and have held three of their four opponents 90 yards rushing or less.
Carolina coach Ron Rivera joked that preparing for Peterson is ''easy in one part because you know he's getting the ball - and hard on the other part because you know he's getting the ball.''
The Panthers know how hard Peterson is to stop.
''He's electric,'' Kuechly said. ''He's got everything you want in a running back. He's quick, strong, powerful, explosive and he can run. He's one of those guys where everybody knows about and everybody knows what he can do.''
The Vikings are expected to start Matt Cassel at quarterback after he led Minnesota to its first win over the season over the Pittsburgh Steelers before the bye.
However, there's a chance the recently signed Josh Freeman could see action, too.
''Switching up the quarterback might change up some things, but we have to be concerned with stopping the run,'' Panthers linebacker Chase Blackburn said. ''Stop the run first and the rest sort of falls in line. If you let the run eat you up it opens up the play-action and a whole can of worms you don't want.''
Blackburn said the Panthers coaching staff showed the defense a statistic earlier this week that stuck with him: Peterson has kept going after ''first contact'' in 72 of his 90 carries this season.
Blackburn said that means the Panthers need as many players as possible running to the ball.
''He runs aggressive. He runs mad,'' Blackburn said of Peterson. ''He likes the contact. He gets into it and embraces it and breaks a lot of tackles.''
Rivera said he's talked to his players this week about matching Peterson's intensity.
''You have to match it because if not he has that opportunity to break one at any time,'' Rivera said.
Panthers defensive end Greg Hardy said Peterson is one of the first people he chooses when picking his team on his Madden video game.
He said Peterson is a beast in the game.
And Hardy knows exactly what he's capable of in real life, too.
Peterson had 159 yards from scrimmage - 83 rushing and 76 receiving - and scored two touchdowns in Minnesota's 24-21 win over Carolina in 2011.
''I've got to hit him in the face and hope he doesn't break my ankles off,'' Hardy said.
Peterson talked this offseason about wanting to run for 2,500 yards this year. He's currently on pace for 1,684 yards rushing.
Peterson said once the season begins he doesn't pay much attention to his numbers.
''I see my Twitter account and it gives me some good feedback, and I'll be like 'Hmm, I didn't know that,''' Peterson said. ''The other day they were saying that compared to last year, I'm like 30 yards ahead of where I was last year, and I finished with 2,000 yards then. So it's like, you don't know.''
Hardy said the Panthers are out to be an obstacle in Peterson's chase at NFL history.
''He's awesome,'' Hardy said. ''I play with him on Madden. I don't know what else you want me to say. I'm a defensive end. He's a running back. He's going to run. I'm going to try to break his neck.''
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