Mitchell (knee) practiced in a limited capacity Thursday, Nick Wagoner of ESPN.com reports.
Not only did Mitchell work with the 49ers training staff on the side Thursday, he mixed into some drills, too. The activity was notable considering he didn't participate at all Wednesday as he continues to tend to knee irritation. The issue didn't stop Mitchell from tallying 21 touches on 36 offensive snaps this past Sunday against the Texans, as opposed to one touch on 19 such plays between reserves Jeff Wilson and JaMycal Hasty. Assuming Mitchell gains clearance to play this weekend at the Rams -- whether it's on Friday's injury report or prior to Sunday's 4:25 p.m. ET kickoff -- he should remain San Francisco's lead running back Week 18.