Mostert picked up eight yards on his lone target and was held for no gain on one carry during Sunday's 38-27 loss to Kansas City.
Mostert had not recorded a touch during the 49ers' first two games but was involved in the action on Sunday. With C.J. Beathard now in at quarterback, it would make sense for San Francisco to lean more heavily on the run, particularly against a Seahawks defense that has been gashed. The question is how many of those hypothetical carries would go to Mostert, who sits behind established veteran Alfred Morris and early-season dynamo Matt Breida. The likely answer is not many.