Mitchell (concussion/knee) isn't practicing Wednesday, Nick Wagoner of ESPN.com reports.
Mitchell didn't practice last week and was ruled out two days in advance of the 49ers' overtime win over the Bengals. Jeff Wilson filled in as the lead back with 13 carries for 56 yards, but Kyle Juszczyk and JaMycal Hasty received most of the playing time in passing situations. Meanwhile, wideout Deebo Samuel served as a secondary option on the ground, taking eight carries for 37 yards and a touchdown. The concussion seems to be a bigger obstacle than the knee injury in terms of Mitchell's availability for the 49ers' upcoming game this Sunday against Atlanta.