Coach Kyle Shanahan said Friday that McCaffrey (Achilles) won't return to practice next week, Nick Wagoner of ESPN.com reports.
It means McCaffrey will miss at least one more game, leaving either Jordan Mason (shoulder) or Isaac Guerendo as the lead back for a Super Bowl rematch with the Chiefs on Sunday, Oct. 20. Mason suffered an AC joint sprain during Thursday's win over Seattle, leaving Guerendo and Patrick Taylor to handle backfield snaps after halftime.