MINNEAPOLIS—In an effort to preserve the running back's aggressive fumbling style, Vikings coach Brad Childress announced Monday that the training staff would not attempt to alter Adrian Peterson's two-point technique for loosely carrying the football. "When you have a great natural fumbler like Adrian Peterson, you don't want to mess with that," Childress said. "That's just raw talent right there. Nobody can expose the ball exactly the way he does. You can't teach that." Peterson has reportedly spent the off-season working with NFL veterans Warren Moon and Dave Krieg to improve his dropping mechanics.