EDEN PRAIRIE, Minn. (AP) - Adrian Peterson is only getting better as the season wears on, producing at a level that matches what he did before going down with a major knee injury last December.

The problem for the Minnesota Vikings is that all that success on the ground isn't doing a thing for their passing game. While Peterson has topped 100 yards in three straight weeks, Christian Ponder has only gotten worse. In two of those games, Ponder failed to top 65 yards passing.

That flies in the face of the traditional thinking that a good ground game will open things up for big plays down the field.

Peterson missed practice on Thursday because of an illness, but is expected to play against the Detroit Lions on Sunday.

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