San Francisco head coach Kyle Shanahan said that Robinson is facing a recovery timeline of 3-to-6 weeks after sustaining a high-ankle sprain in Sunday's 35-13 win over the Dolphins, Nick Wagoner of ESPN.com reports.
Shanahan noted that Robinson will most likely be placed on injured reserve, though the 49ers haven't finalized any decisions since the team can only bring back eight players from IR and already has a lengthy injury list two games into the season.