The Vikings have announced a couple of roster moves on Wednesday. Minnesota has signed running back Jermar Jefferson and waived running back Jordan Mims. AdvertisementAdvertisement AdvertisementLast year, Jefferson appeared in two games for the Cardinals, playing exclusively on special teams. He was most recently with the 49ers for a brief stint during this year's offseason program. He also was with the 49ers for a brief stint during the offseason program this year.