Mostert rushed seven times for 53 yards in Sunday's 34-10 preseason win over the Raiders.
Mostert garnered all of San Francisco's running-back touches on its first offensive drive and was highly efficient with his opportunities. He then saw rookie Trey Sermon incorporated on the second series, and fellow tailbacks JaMycal Hasty and Wayne Gallman shine afterward. Although Sermon should factor prominently in the 49ers' backfield rotation, Mostert seems the most likely candidate to start Week 1 versus the Lions, which would give him good upside as the leader of an often dominant running scheme.