Their rivalry on the football pitch was epic. Off the field though, Manchester City's Roberto Mancini has high regards for his counterpart at Manchester United and has said that Alex Ferguson is the best manager football saw in the last 27 years.
In a report published in the Guardian, Mancini said he sent a letter to Ferguson after he announced his retirement earlier this week. "Yeah, I sent a message. I sent a letter," he said. "It is private and confidential."
Hailing Ferguson's achievements, Mancini voiced his doubts on whether football will ever find another manager who will be able to replicate the feat of the 71-year-old.
"Everyone can have his opinion but one manager who stays for 27 years in the same club and won every trophy for 27 years is an incredible situation. I don't think there will be another manager like him. In Europe, there are other good managers. I don't know if you can say Sir Alex is the best but he is the best in the last 27 years," the Italian said.
Mancini led Manchester City to the Premier League title in 2011-12, edging out Manchester United on the basis of goal difference. The contest between the two arch-rivals made Ferguson commit to taking the title back the following year.
Although there were several occasions when Ferguson and the Italian manager got embroiled in a war of words, Mancini says he has always taken fond memories from wins and defeats against Manchester United.