Glasgow born inside forward Jimmy Long began his professional career with Clyde in 1898 and came south to join First Division Grimsby Town early in 1902, making his Football League debut at Sheffield United that February. Although Grimsby were relegated the following season, Long stayed at the club until the 1904 close season, when he signed for Southern League Reading after 13 goals in 59 appearances for The Mariners. He spent two seasons at Elm Park before returning to Football League action signing for Derby County in the close season of 1906. Although he top scored in 1906-07 with 10 goals, Derby were relegated in his first season, and he stayed one further season before retiring (possibly through injury?) after 20 goals in 66 appearances for The Rams.