The NFL is investigating former Jets coach Eric Mangini's role in the team's failure to list Brett Favre's arm issue on their injury reports last season. Mangini was fired after last season, but was Favre's coach during his one year in New York. Jets general manager Mike Tannenbaum admitted last week that the club should have listed Favre, who had a torn biceps tendon, as "probable" on their injury report for the last four or five games. "Since he was head coach of the Jets at the time, we are reviewing his role in the situation as part of the overall review," NFL spokesman Greg Aiello said in an e-mail response to The Associated Press.