One of the most interesting backfields in the NFL this season is in Minnesota, where the Vikings don't really have a clear answer for who will back up Alexander Mattison. After the team moved on from Dalvin Cook, Mattison has been elevated to a larger role, and now Mattison's old role is up for grabs.Will it be Ty Chandler, Kene Nwangwu, or DeWayne McBride that earns that role? Let's take a look at recent updates to get a sense of who will have the role.Who is the leader to back up Vikings ...