On 3 October 1891, the Saints played their first FA Cup-tie, a 4-1 win at Warmley in the First Qualifying Round. The following Saturday, they lost 2-0 to the 93rd Argyle & Sutherland Highlanders, in an exhibition match at the County Ground.

The St. Mary’s committee members were so impressed by two of the soldiers, John Fleming and John McMillan, that they signed them immediately, as reinforcements for the next round of the Cup, to be played a fortnight later.

Both men duly made their debuts in a 7-0 demolition of Reading.

Centre-forward, Pte “Jock” Fleming, scored a hat-trick. But the committee had failed to complete these signings at least 28 days before the tie, so the Saints were expelled from the competition. While that was it for Sandy McMillan, Jock continue to play in friendlies for St Mary’s, until December, when he was posted to India. When he left the army in May 1892, he had a couple of seasons in the Football League, first at Aston Villa, scoring twice on a false-dawn debut, and then with Lincoln City, of the League’s newly-formed Division II. Whereupon, he returned to non-league football in Scotland.