Mustapha (ankle) was spotted working off to the side of 49ers' practice Monday, David Lombardi of The San Francisco Standard reports.
Mustapha was considered day-to-day after exiting San Francisco's Week 6 win over the Seahawks with a low-ankle sprain. His participation later in the week will provide the best indication on whether the rookie safety can return for the 49ers' Week 7 matchup against the Chiefs.