Smith injured his left knee in the third quarter as he threw a block allowing safety Chris Clemons to recover a Buffalo fumble. Smith has not returned to the game since the play.
The Dolphins replaced Smith with Bryan McCann. Smith has has only missed one game in his career, and has been the starting cornerback for Miami since his rookie season.
Miami was already short at cornerback on the day, with Nolan Carroll ruled out. The team started Dimitri Patterson in Carroll's spot, despite Patterson only joining the team this past Monday.
The Dolphins face the New England Patriots next week and will need all the cornerback help they can get.