The National Football League reportedly sent a letter to the New York Times' legal counsel Monday demanding a retraction to the outlet's story last week about the NFL's research into concussions.
Joe Pompeo of Politico Media reported Tuesday that NFL attorney Brad S. Karp called the New York Times article "false and defamatory" in the letter. The league also "seemed to threaten the possibility of further legal action," according to Pompeo, and it requested those who worked on the story release all of the information gathered for the piece.