Mitchell (concussion/knee) didn't practice Thursday, Matt Maiocco of NBC Sports Bay Area reports.
While he has yet to practice since picking up a concussion Week 13, Mitchell has been seen working off to the side with the 49ers' training staff on back-to-back days, according to Nick Wagoner of ESPN.com. With no on-field work to speak of this week, though, Mitchell may be trending toward a second straight absence Sunday against the Falcons. If the preceding is confirmed -- whether it comes on Friday's injury report or 90 minutes before Sunday's 4:05 p.m. ET kickoff -- the 49ers would turn to Jeff Wilson for most of the RB reps, with Kyle Juszczyk, JaMycal Hasty and even Deebo Samuel mixing into the backfield.