The Minnesota Vikings have released Jamarca Sanford from short-term injured reserve (which is not the same as injured reserve-designated for return) and have reached an injury settlement with the former starting safety. What generally happens in these cases is that the player and his representation disagree with the team over the likely length of their injury, so they cannot reach an injury settlement in the offseason. As a result, they put the player on injured reserve to wait out how long he will take to recover, then release him.
In this case, something about the injury must have clarified itself to one or both parties, so they could reach an injury settlement and release him outright. He will not return to the Vikings, per Darren Wolfson.