McKenna played his club hurling with the famous South Liberties club in Limerick and enjoyed much success. He won his first senior county title in 1972. Four years later in 1976 McKenna captured a second county medal, however, South Liberties were later defeated by Glen Rovers in the Munster club final. 1978 saw him add a third county title before collecting a fourth county medal in 1981. Once again South Liberies were later defeated by Mount Sion in the Munster club final.
McKenna first came to prominence on the inter-county scene as a member of the Limerick minor and under-21 teams. In 1971 he joined the Limerick senior team, however, it would take some time before he gained a regular splace on the team. In 1973 McKenna was a non-playing substitute when Limerick defeated Tipperary to win the Munster title for the first time since 1955. Although he played no part in that game he was on the starting fifteen for the subsequent All-Ireland final against Kilkenny. Limerick outplayed Kilkenny throughout the eighty minutes and captured a 1-21 to 1-14 victory, giving McKenna his sole All-Ireland medal. In 1974 he won his first Munster title on the field of play as Limerick trounced Clare in the provincial final. McKenna’s side later faced Kilkenny for the second year in-a-row, however, 'the Cats' had a comfortable twelve point victory over Limerick. The team faded out of the limelight for a number of years, however, Limerick bounced back in 1980 with McKenna capturing a second Munster title. His side later took on Galway in the championship decider, however, for the first time since 1923 the men from the West captured the All-Ireland title in an emoional display at Croke Park. Limerick were back in 1981 with McKenna adding a third Munster medal to his collection. Unfortunately, Limerick were later defeated by Gaway in an All-Ireland semi-final replay. Now in the twighlight of his career McKenna captured a National Hurling League medal in 1984. He retired from inter-county hurling in 1985.
In retirement as a player McKenna took over as manager of the Limerick senior team in 2005. His tenure was not a happy one and he resigned following Limerick’s defeat by Tipperary in the 2006 Munster quarter-final.