They were two proud Glaswegians who ended up managing in the Granite City and in England.
And Sir Alex Ferguson has spoken of how he is “deeply saddened” following the death of former Celtic captain Billy McNeill at the age of 79.
The former Scotland international made over 800 appearances for the Glasgow giants from 1957 to 1975 and wore the captain’s armband as the Parkhead side became the first British club to win the European Cup in 1967, under the stewardship of Jock Stein.
After hanging up his boots, McNeill moved to the north-east of Scotland and was instrumental in recruiting the likes of Gordon Strachan and Steve Archibald; talented individuals who subsequently became stars at Pittodrie in the 1980s with Ferguson at the helm while his charges achieved European glory of their own by winning the European Cup-Winners Cup in 1983.
These shining luminaries of Scottish football also faced each other during their playing days, with McNeill captaining Celtic and Ferguson playing as a forward for Rangers.
And it was another quirk of their careers that they both managed in Manchester, with Ferguson excelling at United after McNeill had been in charge at Maine Road.
Sir Alex said on Tuesday: “I, like everyone in Scotland, am deeply saddened to hear of the passing of Billy McNeill.
“He was a giant in Scottish football, a man with an incredible presence and I’ll always cherish the fact that we entered professional football at the same time.
”We played against each other on many occasions and, as anyone who played against him will testify, he was the fairest of players.
“He was also a truly good man and will be a loss to everyone who knew him.
McNeill was nicknamed Cesar after the film star Cesar Romero, one of the cast of the original “Ocean’s 11”.