Southport born inside forward John Carlin started his football career with Firvale in 1893 before joining Tranmere Rovers in 1896, moving to near neighbours Birkenhead in 1899. In November 1899 he joined First Division Glossop making his Football League debut against Sheffield United in December and having a single season with The Hillmen as they were relegated into the Second Division, scoring once against Stoke in February 1900 in 8 appearances. He joined Second Division Barnsley in November 1900 scoring 10 goals in 52 appearances before being signed by First Division Liverpool in December 1902. He first appeared in Liverpool’s forward line at Stoke on 17th January 1903. This was his only game of the 1902-03 season and was the only match missed by Liverpool’s star striker Sam Raybould, who scored 32 times in 34 games.
In view of the club’s reliance on Raybould to score, perhaps it was not surprising that Carlin’s debut for the club was one of only six matches in which they failed to score during the League campaign. The joint Everton/Liverpool programme commented on him in a preview to the 1904-05 season: “Is so clever and has such knowledge of the game that one is forced to explain “What a pity it is that he is only a little ‘un.” He is apt to be lost in a melee in front of goal.” Carlin never settled down in Liverpool’s first eleven and the highest number of appearances he made in a single season was the 16 he managed during 1905-06 when he scored six goals, a vital contribution to the club’s second League Championship title, having only played 5 times the previous campaign as Liverpool won the Second Division Championship. He joined Preston North End in the close season of 1907 after 8 goals in 35 appearances for The Reds, and spent two seasons at Deepdale scoring 5 times in 33 appearances before retirement in 1909.