Ryan O'Callaghan

Here he is ... the KC Chiefs trainer who helped save a closeted gay NFL player from killing himself, David Price, tells TMZ Sports he was "elated" to find out he had such a positive impact. The player is ex-offensive lineman Ryan O'Callaghan -- who recently came out publicly on Outsports.com after…

Ex-NFL lineman Ryan O'Callaghan -- who played for the Patriots and the Chiefs -- has come out as gay ... and says it was an NFL team staffer who helped save his life. O'Callaghan was selected by New England in the 5th round of the 2006 NFL Draft -- and protected Tom Brady in 2007, the year they…