Toby Gerhart is expected to be the Vikings' primary back against the Jaguars Sunday. If Adrian Peterson (knee) is active, he'll have "limited exposure" according to coach Leslie Frazier. That leaves the feature back job to Gerhart, who has proved he is capable of handling big workloads before. In the five games that Peterson has missed over the last two seasons, Gerhart has averaged 21.0 touches. "We feel like we don't have to change any of our plays. We're very confident and comfortable with Toby being our lead back if that's the case," Frazier said.