NFL Players Association executive director Lloyd Howell Jr. resigned late Thursday, ending his embattled two-year tenure as the leader of the union. "For this reason, I have informed the NFLPA Executive Committee that I am stepping down as Executive Director of the NFLPA and Chairman of the Board of NFL Players effective immediately. I hope this will allow the NFLPA to maintain its focus on its player members ahead of the upcoming season." According to sources, the report triggered the NFLPA to hire Ronald C. Machen of law firm Wilmer Hale to review Howell's activities as executive director. Howell succeeded DeMaurice Smith as the head of the NFLPA, which represents nearly 2,000 pro football players.