[3][4] In 1945, O'Flanagan, together with his brother Kevin, was a member of the Bohs team coached by Jimmy Dunne that won the Dublin and Belfast Intercity Cup.
On 30 September 1946, he was working a pub in Dublin when he received a desperate phone call at 2:30 p.m. asking him to substitute for an injured Irish player in a match against England due to start at 5:30 p.m. at Dalymount Park.
Other members of the touring party included Billy McMillan, Tom Aherne, Robin Lawler, Johnny Campbell and manager Elisha Scott.
Mick was only called up as a late replacement for the injured Davy Walsh and he had spent the previous night entertaining a party of English journalists at Templeogue tennis club.
This helped an Ireland team, featuring Karl Mullen and Jack Kyle, win the Triple Crown, Grand Slam and the 1948 Five Nations Championship.
He ran a pub at 88 Marlborough Street[15] in Dublin's City Centre which is known today as the Confession Box[16] due to its proximity to St. Mary's Pro-Cathedral.