[1][2] His father was born in Fethard, County Tipperary but moved to Cork and worked in the Metropole Hotel.
He played on the school's Harty Cup team for a number of years, beginning as a goalkeeper but later becoming an outfield player.
He was full-forward on the Sullivan's Quay Harty Cup team that beat the North Monastery in 1951 before losing the final to Thurles CBS.
Brohan's performances earned his inclusion on the Munster Colleges inter-provincial team, and he won consecutive All-Ireland titles in this competition in 1952 and 1953.
[3] He also achieved success in Gaelic football that year, when sister club St Michael's beat Dromtarriffe to win the Cork JFC title.
[4] Brohan was appointed team captain for the 1959 Cork SHC, however, Blackrock's season ended with a 3–11 to 3–05 defeat by Glen Rovers in the final.
[5] Blackrock were back in a fourth final in 1961, with Brohan collecting a second winners' medal after the 4–10 to 3–07 defeat of Avondhu.
[7] Brohan brought his senior club career to an end shortly after winning a Cork IFC medal following St Michael's defeat of Dohenys in 1969.
Brohan made his championship debut as a replacement for the injured Tony O'Shaughnessy in the 1954 All-Ireland semi-final defeat of Galway.
The injured O'Shaughnessy returned for the subsequent All-Ireland final, with Brohan claiming a winners' medal as a substitute after the 1–09 to 1–06 defeat of Wexford.
[10] Brohan was suspended from all GAA activity in 1955 after being selected for the Seandún divisional football team and failing to turn up.
He returned to the Cork senior team as first-choice right corner-back the following year and won his first Munster SHC medal on the field of play after a defeat of Limerick in the final.