Fergie snapped up the left-winger from Bristol City after the Scot had a run of exciting form. But Milne failed to make the grade at Old Trafford in three seasons and actually left the club in 1991 for former Hong Kong club Sing Tao Sports Club.
On his worst signing, Ferguson declared: "Ralph Milne. I only paid £170,000 but I still get condemned for it."
At which point Ferguson remembers one he has tried to forget - Eric Djemba-Djemba.
"So good they named him twice," grinned Ferguson, who revealed his misfiring former midfielder, now with Odense BK, had just come in the top four for the Player of the Year in Denmark.