Career
Pierce is the brother of former Arsenal star and fellow Irish international David O'Leary. A week after the Cup Final he signed for Philadelphia Fury where he spent three months. In 1981 he signed for Vancouver Whitecaps before joining Celtic in November 1984.
O'Leary earned youth caps and 7 Republic of Ireland national football team caps while at Milltown, five Republic of Ireland national under-21 football team caps and made three appearances for Rovers in European competition. The tall centre-half made his Celtic debut in a 2–1 victory at Hamilton Accies on 30 January 1985. He came on as substitute in the 1985 final as Celtic came from behind to defeat Dundee United 2–1.
He then made enough appearances to claim a League Championship medal after Celtic pipped Hearts for the title on the final day of the 1985–86 season. He was forced to retire in 1988 due to recurring pelvic trouble. Pierce's son Ryan O'Leary is now a professional football player with Kilmarnock.
Bonner's involvement only lasted a few years, but under O'Leary the business secured numerous contracts with offices, shops and hospitals.