Former Chicago Bears great Gale Sayers has sued the NFL, becoming the latest former player to hold the league accountable for health problems stemming from head injuries. In the lawsuit, which the Chicago Tribune reported was filed in U.S. District Court in Chicago on Friday, Sayers said the league failed to protect him from "devastating concussive head traumas" and that he now suffers from headaches and short-term memory loss. Sayers' lawsuit claims the NFL did not sufficiently warn players that multiple concussions could lead to permanent brain damage, according to the Tribune. According to the lawsuit, Sayers is seeking unspecified damages.