Black turned six carries into 13 yards during the 49ers' 24-14 win over the Broncos on Sunday.
Analysis:Black's longest carry of the day went for five yards, with four of his other touches going for two yards or fewer. With Christian McCaffrey clearly leading the backfield, Black's workload will be volatile on a week-to-week basis and dependant on game script. The 49ers will hit the road for Week 5 in an NFC West showdown against the 3-1 Seahawks.
