The NFL is exporting Matt Cassel football to London this week, and it shouldn’t be the UK fans who are the most worried. That dishonor belongs to the reigning NFL MVP Adrian Peterson.

Peterson has been a top two or three back in the league since he stepped on the field as a rookie in 2007. He’s sliced, diced, mashed and mangled defenses to the tune of 99.2 yards per game for his career, but Peterson will never accomplish the larger goals on his checklist if he can’t get some sort of consistency from the guy handing him the ball.

Cassel becomes the Vikings’ 9th quarterback of Peterson’s seven year career. The only one to get them anywhere near the promised land was Brett Favre, leading Minnesota to overtime of the 2010 NFC Championship Game.

It’s a situation of history repeating itself, both in a positive and negative way. Barry Sanders was one of the greatest and most electrifying running backs to ever play the game. He was on pace to set the NFL rushing record when he called it quits before the 1999 season and his highlights are of the “I don’t believe what I just saw,” variety.

He also, and almost more memorably, finished his career in the unenviable group of stars who never won a Super Bowl.

Now look at Peterson. He runs nothing like Sanders. Barry succeeded by eluding defenders. Adrian does it by running through and past them. AD is a workhorse who thrives on contact and breaking tackles, and he strikes fear into much smaller defensive backs. Stat lines don’t care how a player runs the ball, though. It’s all about the numbers.

• Peterson (6+ seasons): 99.2 ypg, 5.0 ypc, 79 TD, 9 different QBs, 1-3 playoff record, 3 winning seasons
• Sanders (10 seasons): 99.8 ypg, 5.0 ypc, 99 TD, 10 different QBs, 1-5 playoff record, 5 winning seasons

It doesn’t get much more eerily similar than that, and Peterson has to start wondering what his future is with the Vikings. He famously told Sports Illustrated this past offseason that he was going to be the first player to ever rush for 2,500 yards in a season. Instead, teams are able to stack the box against him and Minnesota’s anemic passing game, putting him on pace for just 1,499, a great number for most but mediocre for arguably the league’s best player.

Peterson and his 0-3 Vikes make the trip to London this weekend, and his inevitable highlight reel runs will dictate the emotions of a new generation of NFL fan, but for the first time in his career it seems the control is starting to slip out of the hands of one of the league’s most dominant runners. We study history so we don’t make the same mistakes again, but as the quarterback carousel continues in Minnesota, it appears the Vikings could use a refresher course.