The Manchester United supremo announced his impending retirement yesterday after almost 27 years at the Old Trafford helm, and has rightly been lauded since.
Ferguson will head upstairs having seen his teams lift 49 trophies in total, 38 since he headed south of the border from Aberdeen, and that record alone elevates him to the highest pedestal.
Di Canio, whose managerial career at the highest level is only weeks old, knows he and his counterparts have a long way to go to be even considered in the same bracket, and he is convinced no-one will ever top the Scot's roll of honour.
The 44-year-old: "He is a model in general, he's an icon to reach, which is not possible."
He added with a smile: "Fifteen years for me are enough, I don't know, and then I will finish, bye, bye - because I am 65 now, so I will get to 80 and then finish.
"It's not possible to reach his level, but in terms of what he has achieved and how he was at the right time, in the right place every time...
"The generation changed and he was still modern because he studied the new generation's mentality and then he could treat Beckham like he can treat some of the youngsters when they get to the age he was 20 years ago.
"It means there is a fantastic brain that works well, but it's something you can't match because he is the unique one.
"He is there, let him relax now because what he has done will remain forever in this sport. Even in 50 years' time, everybody will be talking about this unique man and manager.
"What he has achieved is unique."
For all Di Canio believes Ferguson's feats will never be matched, he admits there are lessons all managers can learn from him.
He said: "I saw all the documentaries last night and there is one moment that tells you why he won everything, why he is the unique one.
"On May 11, 1983, he won the European Cup Winners' Cup [with Aberdeen] and on May 21 against Rangers, he won the Scottish Cup.
"At the end of the game, a reporter tried to ask him if he was happy and his face was very dark. He said it was a rubbish performance and that they had to develop a different mentality.
"When you say to your players after you draw 1-1 that we could have done better, they think that's too much - but this is the kind of manager who can become a top manager like he was.
"It's difficult to reach his level, but this is why he won what he won, because he won two cups in 10 days and he was angry with his players. That is a winning manager."
The Black Cats boss could be forgiven for having added affection for Ferguson having made an unexpected appearance in his autobiography.
He said: "I know in his book he said he had three big regrets - one of the three is that he didn't sign Paolo Di Canio.
"I thought he was mad or he was drunk that night, but anyway, it made me proud.
"I was in Italy and my friends were saying, 'Have you seen what he said?'. I said probably he had been drinking that night.
"But talking about me, now for the rest of my career as a manager a big regret will be that I won't stand as an enemy in the next dugout to him because it would be fantastic to have a chance to beat the professor, the football god.
"I am very sad."