For a team that was so unabashedly devoted to Adrian Peterson last season, the Minnesota Vikings have seemed surprisingly unwilling to rely on the reigning NFL MVP the same way this year. The Vikings got to the playoffs last season largely by handing Peterson the ball when everyone knew they were going to run, and watching him break through both tacklers and logic on his way to 2,097 yards. This year, with a passing game that's been again unable to carry its weight and a defense that has gone from sturdy to shoddy, Peterson has been marginalized. He's carried just 36 times in the Vikings' last three games, gaining no more than 62 yards in any of them. But the interesting thing about those games is that Peterson was only really stopped in one of them, on Oct. 21 against the New York Giants. when he ran 13 times for 28 yards. In the other two games, against Carolina and Green Bay, Peterson averaged 6.2 and 4.6 yards per carry, respectively, but he didn't get his carries either because the Vikings were too far behind to run the ball (against the Panthers) or were rarely on the field (against the Packers). So, what's changed? Well, the Vikings were built to play with a lead last season, when they could run Peterson and turn loose their defensive line on opposing quarterbacks. They're probably still built to play that way; they just haven't had leads because their defense has been so much worse. As a result, Peterson's production has suffered: he's carried only five times in the last three weeks when the Vikings were tied or ahead, according to ESPN Stats & Information. That's meant Peterson has had to fight for carries when the Vikings have been trailing, and it's given him fewer chances to run behind Pro Bowl fullback Jerome Felton, who helped Peterson average nearly 7 yards a carry from two-back sets last season. In the Vikings' last three games, Felton has been on the field for just 18 Peterson carries. Last year, the Vikings stuck with the Peterson-Felton combo for 53 carries in eight games where they were trailing, and Minnesota came back to win two of those games.