"The next manager will find it impossible to replicate what he's done," the Doc told the Manchester Evening News. "The new manager will do his own thing, but to overtake him will be impossible. What he's done will never be done again.
"The next guy might not get the time because he will be expected to just pick up the reins and carry on the success, when usually you would rather take over a team that is doing badly.
"Even Jose Mourinho would have no chance of being as successful than him. Given the amount of time Sir Alex has been at the club, there is no way that the next manager could match his record."