He played as a goalkeeper for the St Ronan's club and at senior level for the Roscommon county team.
Sheerin earned the Number One Jersey by 1978, and he received his first of five Connacht SFC medals that same year.
After this, Sheerin resumed his former position again, and was a goalkeeper for the 1980 All-Ireland Senior Football Championship Final.
[1] In the early 1990s, Roscommon won two consecutive Connacht titles, defeating Galway in 1990 and Mayo in 1991 with the help of a replay.
Sheerin later quit the job in 2000 after three seasons due to Leitrim defeating Roscommon in the Connacht SFC semi-final.
[1] Sheerin's inspirations include Brian McAlinden of Armagh, Paddy Linden Monaghan, and Martin Furlong of Offaly.