Here's a key matchup in Sunday's Vikings-Lions matchup:
Vikings RB Adrian Peterson vs. Lions front seven
Week Four was the first game in which Vikings QB Christian Ponder was not effective throwing the ball, as the Lions kept everything in front of them, prevented the big plays and got him off his spots. That game was with Percy Harvin on the field, and he's listed as "extremely doubtful" to play this Sunday. That's bad news for Ponder, but it's perhaps worse for Peterson.
He was effective running the ball in the first matchup, gaining 105 yards on 21 carries with the majority of those yards coming after contact. At that point of the season, Peterson was still showing a bit of rust from the offseason, though not much; he just didn't have that extra gear at this point of the season, and since then he has run for 64- and 74-yard gains in Weeks Eight and Nine.
In the first matchup, the Lions repeatedly were frustrated. They hit him several times close to the line of scrimmage but couldn't bring Peterson down. Between the tackles, he had gains of 12, 18 and 15 yards that will have to be the kind of carries Peterson will have to execute without the benefit of a passing game. The Vikings have not been successful using play-action passing, so the Lions will be playing run most of the way.
Peterson's one-cut ability is even stronger now than it was when the two teams first met, but the overall offense is worse. MLB Stephen Tulloch and the Lions' linebackers have stepped up their play of late and have been solid most of the season against the run. Ganging up on Peterson early and flipping the frustration around on him might be the way the Lions have to go about business. He has ripped off two big runs each of the past two games en route to big games, so that's the last thing the Lions want to have happen on the road.