Ferguson was manager of St Mirren for 4 years (1974 – 1978), transforming the team remarkably from the lower half of the old Second Division to First Division champions in 1977. He also contributed to discover talents like Billy Stark, Tony Fitzpatrick, Lex Richardson, Frank McGarvey, Bobby Reid and Peter Weir …
St Mirren is also the only club ever to sack Ferguson which is claimed wrongful dismissal although rumours has it that Ferguson was sacked for various breaches of contract including unauthorised payments to players, intimidating behaviour towards office secretary and Ferguson having agreed to join Aberdeen. Ferguson was said to be “particularly petty”, “no managerial ability” and “immature” by St Mirren chairman.
Ferguson even asked member of the squad to go to Aberdeen. Talking about this leaving, managers of St Mirren expressed regret over what happened but blamed Aberdeen for not approaching his club to discuss compensation.
In 1977, Ferguson turned down the manager’s job at Aberdeen but joined after 1 years after the temporary fulfilment of Billy McNeill.
Ferguson joined Aberdeen in June 1978 when Aberdeen were one of Scotland’s major clubs playing well, had not lost a league match since the previous December, having finished second in the league the previous season but they won the league only once in 1955 under Dave Halliday. Although Ferguson became the team manager, he had trouble winning the respect of some of the older ones. Hence, the season did not go well as expected, and Aberdeen reach the semi-final of the Scottish Cup and the Scottish League Cup Final, but losing both matches and finishing fourth in the league. The following season, Aberdeen lost the 1979–80 Scottish League Cup Final to Dundee United after a replay which lead to Ferguson took the blame for the defeat.