49ers RB Raheem Mostert rushed for 53 yards on seven carries in Sunday's victory over Las Vegas.
Mostert did all of his damage in the very first series for the 49ers. He was uber-efficient, averaging 7.6 yards per attempt. Trey Sermon replaced him on the next drive, and finished the game with seven carries for 37 yards. Both tailbacks will almost certainly split carries throughout the season, with Sermon possibly earning the lion's share of touches later in the year. While this is a great situation for the 49ers, it's likely to be a frustrating one for fantasy managers.