Mixon (ankle) didn't participate in Wednesday's practice, Geoff Hobson of the Bengals' official site reports.
While Mixon said that his injured ankle is feeling better, he remains day-to-day after getting banged up in the Week 1 loss to the Seahawks. The Bengals hope to have Mixon available for Sunday's tilt against the 49ers, but if he ends up limited or ruled out for the contest, expect Giovani Bernard to handle the lead-back role.