Mitchell (knee) was a non-participant at Wednesday's practice, Matt Maiocco of NBC Sports Bay Area reports.
Mitchell put an end to a three-game absence this past Sunday against the Texans, resuming his role as the 49ers' top running back with 23 touches for 130 yards from scrimmage and the first receiving touchdown of his career. The rookie sixth-round pick has been a revelation when healthy this season, with five 100-yard performances on the ground in 10 appearances. But it appears Mitchell's knee injury continues to bother him, so his status will be one to monitor throughout the week to ensure he isn't in danger of sitting out a seventh contest of the season Sunday at the Rams.