McLean, who has died at the age of 83, shook up Scottish football along with Ferguson in the 1980s as their Dundee United and Aberdeen sides broke the dominance of Celtic and Rangers. Both took their teams to European finals.
Dundee United won the League in 1983 under McLean, who also led them to two League Cup triumphs, six Scottish Cup finals, the European Cup semi-finals and a UEFA Cup final.
United were not even the best team in Dundee when McLean took over in 1971, but he transformed the club during 22 years at the helm.
"When you think back, it is almost absurd what he achieved," said Ferguson. "He took a club and changed it completely. He took players and made them better.
"His legacy in football is that anyone who came across him knows he was a fantastic coach.
"Yes, he could be prickly. But deep down he was a good man. He was always ready to help. I learned so much from him."
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