The Vikings designated Smith (ankle) for return from injured reserve Wednesday, Chris Tomasson of the St. Paul Pioneer Press reports.
The team now has 21 days to activate Smith to the roster or else keep him on IR for the rest of the season. He'll presumably rejoin the Vikings for the playoffs, if not one or both of the final two games of the regular season, though in a secondary role behind standout trade acquisition T.J. Hockenson.