I think Peterson generally guards the other team's best receiver... that was the big part of the discussion a few years ago about who was the best Corner in the league. Richard Sherman wouldn't follow the other team's best receiver whereas Peterson would man up the top guy on both sides of the field.
Now, if that best receiver is playing inside in the slot does Peterson guard him? That I do not know... but I do not think so. I believe the Honey Badger plays nickel for them so peterson stays on the outside against the best WR playing outside.
Haven't watched the Cardinals much this year though so don't know the full scoop of their secondary.
