Sir Alex Ferguson's unrivalled record at Manchester United means he is assured his position as a club legend for the rest of time.
However, the Scotsman did oversee a decision back in 2012 - letting Paul Pogba leave on a free transfer - that has ultimately come back to cost the Red Devils to the tune of £89 million.
The story behind Ferguson's decision not to hand the then teenage Frenchman a new contract at Old Trafford has always focussed on the veteran manager's dislike of Mino Raiola, the super-agent who represents Pogba.
And now, in an in-depth interview with the Financial Times, Raiola has shed new light on the 'negotiations' four years ago, including the foul-mouthed response Ferguson had when the agent put forward his demands for his client.
At the time, Pogba was on the fringes of the United first-team and had made only a handful of brief appearances for Sir Alex.
That, then, might explain why Ferguson was so furious when both player and agent came to him with what the Scottish boss clearly thought were outlandish demands.
This, per Raiola, is how it went down...
"Ferguson to Raiola: I don’t talk to you if the player is not here. Raiola: Get the player out of the locker room and sit him here.
"Pogba enters. Ferguson to Pogba: You don’t want to sign this contract? Pogba: We’re not going to sign this contract under these conditions.
"Ferguson to Raiola: You’re a t**t."
Now that's a pretty harsh reaction, even from a manager famed for the hairdryer treatment.
Apparently, though, Raiola wasn't too bothered, mainly because he didn't know what the x-rated word meant.
That didn't stop Ferguson using the same expression again when the agent tried to argue United's offer for Pogba wasn't up to scratch.
"Raiola: This is an offer that my chihuahuas — I have two chihuahuas — don’t sign.
"Ferguson: What do you think he needs to earn? Raiola: Not that. Ferguson: You’re a t**t."
Clearly, negotiations didn't progress much further than the heated exchanged described above because, by July 2012, Pogba had left United and was bound for Juventus.
Four years on, Pogba is back at Old Trafford and on far more money than his agent was demanding back in 2012.
You have to wonder whether that would ever have happened had Ferguson opted to stay on a few more seasons rather than heading for retirement.