Mostert (concussion) rushed six times for 58 yards and a touchdown, adding two catches for 42 yards in Monday's 24-15 preseason win over the Broncos.
Mostert not only returned from the concussion he suffered during the first week of the preseason, but he also appeared to be in midseason form by ripping off multiple big gains Monday. The 27-year-old was facing Denver's second-stringers, but he did flash big-play ability in a short spurt last season (7.7 YPC on 34 attempts). Mostert is currently fourth on the 49ers' depth chart, but he is getting increased looks while Jerick McKinnon (knee) continues to battle back from injury. Even if the latter is ready for the start of the season, Mostert's ability to contribute on special teams -- combined with the shaky health of the team's starters -- should keep him around come Week 1.