His father John was a provincial high jump champion.[1] His brother Sean achieved county records in the decathlon and the discus throw and narrowly missed the 1984 Summer Olympics with a hamstring injury.[1] Sean, as well as their brothers Eugene, Joseph and Declan, all played for Red Hughs.[1]
Carlin returned to the team and played in both the 1989 Ulster Senior Football Championship final and replay.[1] They were two of only six appearances he made for his county in championship football.[1]
Carlin left the county team at the end of 1990 after informing manager Brian McEniff of his decision.[1] Thus he missed the 1992 All-Ireland Senior Football Championship Final, which Donegal won.[1] At the local homecoming, clubmate Donal Reid gave him a special mention and invited him onto the stage.[1] After being awarded Donegal Player of the Year in 1993, Carlin was prompted to make a brief return for his county in 1994.[1]