Born in Barrhead, Renfrewshire, Sloan joined local Junior side Arthurlie in 1942 and, after switching from centre forward to the right wing, became a regular in the first team.
He agreed, however, to stay with Arthurlie for the duration of their Scottish Junior Cup campaign, eventually helping them to the final, where they lost 2–0 to Fauldhouse United.
McLean's assistant, Tommy Walker, inherited the role of manager and, after an initial settling-in period, started to remould the side in his image.
After two close games were drawn 1–1, the pair enjoyed their revenge on former manager Walker as Motherwell won the second replay 3–1, reaching the final for the fourth time in their history.
They had lost all three previous finals, to Celtic (twice) and Clyde, but Sloan helped the Steelmen overcome the weight of history to record a comfortable 4–0 win over Dundee.