At club level he played as a centre-back for Bruree and was the left corner-back on the Limerick senior hurling team that won the 1973 All-Ireland Championship.
[1] O'Brien's skill was recognised at an early age when he won a South Limerick school's medal with Bruree National School, before an unrewarding spell at Rathluirc CBS.
His career at club level with Bruree spanned three decades.
He made his first appearance for the Limerick senior hurling team during the 1966-67 National League and enjoyed his greatest successes as a defender over the following decade.
In 1973 O'Brien became the first Bruree clubman to win an All-Ireland Championship medal, having earlier won Munster Championship and National Hurling League titles.