The Giants released Downs on Tuesday, Jordan Raanan of ESPN.com reports.
Downs re-signed with the Giants, Michael Eisen of the team's official site reports.
The Giants did not tender Downs, making him an unrestricted free agent, Jordan Raanan of ESPN.com reports.
Downs is on track to fill a starting role at one of the Giants' inside linebacker spots in Monday's season opener against the Steelers, Tom Rock of Newsday reports.
Downs agreed to a new contract Monday, Dan Duggan of The Athletic reports.
Downs was placed on waivers by the Vikings on Tuesday.
The Vikings promoted Downs to the active roster Saturday.
Downs played 12 snaps on special teams in Friday's preseason win over Seattle, Andrew Krammer of the Minneapolis Star Tribune reports.