He played Gaelic football with his local club Glenamoy and was a member of the senior Mayo county team from 1983 until 1990.
A shortage of underage activity in Glenamoy resulted in Irwin first playing competitive Gaelic football as a schoolboy with Lacken Cross Vocational School.
Irwin also earned inclusion on the Mayo vocational schools' team and won an All-Ireland VSSFC title in 1982.
Irwin later made the starting fifteen and was in goal when Mayo suffered a defeat by Cork in the 1989 All-Ireland final.
[5] Irwin left the inter-county scene in 1993, by which time he had also claimed five Connacht SFC medals.