Mitchell (hamstring) is not expected to play in Saturday's preseason opener, Matt Maiocco of NBC Sports Bay Area reports.
The 49ers have a numbered of injured running backs also not playing Saturday, including Christian McCaffrey (calf) and Isaac Guerendo, but it doesn't seem as if backup Jordan Mason will see extensive snaps. As a result, Cody Schrader, Matt Breida and Patrick Taylor could see plenty of opportunities.