 After three years in the north-west O'Riordan mutually agreed to leave Sligo and returned to England after spending seven years as manager of 2 League of Ireland clubs.Besides his commitment to his League of Ireland employers both in Galway and Sligo he was well known in the West of Ireland for helping the local Technical Colleges both in Galway and in Sligo and enhanced his reputation in both cities when he guided the Galway IT Men's Team to the Ireland National Senior League title and later the Senior Women's Team from Sligo IT to the National League title of Ireland.He left Ireland and in 2004 and subsequently joined the Sheffield United coaching staff under then manager Neil Warnock, whom O'Riordan played for when Warnock was in charge of Notts County.