Kevin Keegan resigned as manager of Newcastle United on Thursday, less than eight months after taking charge of the Premier League club for the second time.In a statement issued through the League Managers Association, Keegan said he had been left with "no choice" other than to leave because of the way the club was being run."I've been working desperately hard to find a way forward with the directors but sadly that has not proved possible. It's my opinion that a manager must have