The Vikings signed running back Bronson Hill to replace Sankey on the roster Saturday.
Sankey, a second-round draft pick by Tennessee in 2014, joined Minnesota's practice squad late last season. He was hurt at the end of a 14-yard run at Buffalo on Thursday and left the stadium on crutches. Sankey can be placed on injured reserve after clearing waivers.
Hill played in three games last season for Jacksonville. Undrafted out of Eastern Michigan in 2015, Hill is joining his sixth NFL team.