Sir Alex Ferguson is not someone who usually finds himself the source of mockery.
As Manchester United manager, the Scot won it all - from 13 Premier League titles and five FA Cups, through to two Champions League crowns.
But despite his status as the greatest manager in the history of the Premier League, Juventus’ Gianluigi Buffon has wasted little time in sticking the boot in when it comes to Fergie.
The source of the Italian’s ire is the ex-Red Devils gaffer’s decision to bring Paul Scholes out of retirement rather than give Paul Pogba a first-team opportunity at Old Trafford a few years back.
It was the final straw for the Frenchman, who opted to depart the club on a free transfer for Juve.
"I have been in football many years, but the decision of Sir Alex Ferguson and Manchester United to not play Pogba and let him leave is one of the strangest I have ever seen," Buffon told the Daily Express.
"After just a few training sessions we saw how good he was. It cannot have been the same player they saw in Manchester - we thought they maybe needed glasses.”
Yet Pogba is unlikely to be the only United player Ferguson regrets letting go. Here are his five most lamentable transfer decisions.
5. Jaap Stam
Manchester United enjoyed a hat-trick of Premier League titles with the Dutchman marshalling the defence, but he was sold to Lazio after Ferguson clashed with the player over allegations made about the club in the stopper’s autobiography “Face to Face.”
Years later the Scot would admit in an interview with The Daily Mirror that the sale was a fatal error, with replacement Laurent Blanc struggling to fill the void left by the Holland international.
"It was one of the mistakes I made – hopefully I haven't made too many – but that was one," he told the news provider.
4. Gerard Pique
The Red Devils pulled off a major coup in recruiting then-defensive midfielder Pique from Barcelona’s youth setup, with United not required to pay the Catalans a penny for the Spaniard.
But despite staying on the books at Old Trafford for some four seasons, the defender failed to break into the Manchester United first-team on a regular basis and decided to return to Barca, having caught their eye during a season-long loan at Real Zaragoza.
Speaking to Sky Sports before the 2009 Champions League final, Ferguson admitted his error but cited some outside influences.
"I have always liked the boy. I did expect him to reach this level so quickly," he said.
"I always thought he would do well. We were disappointed to lose him but we understood at the time that his family desire was to go back to Barcelona."
3. Giuseppe Rossi
The Italian-American was always tipped for a bright future at Old Trafford, but despite five solid Premier League appearances that included a fine goal against Sunderland, Rossi was never really given a chance to shine at the club.
Everything changed in 2007 when the forward was loaned to Parma, who he helped to avoid relegation with nine goals in 19 games. United then accepted a permanent offer from Villarreal for the striker, which contained a buy-back clause that was never activated.
In an interview with The Express last year, ex-United coach Rene Meulenstein expressed regret over the entire deal.
"Personally, I would never have let him go because you could see that he was going to be a major star in the Premier League,” he told the news provider.
"He would have been the equivalent of David Silva, Samir Nasri and Juan Mata, players who play in the middle of the lines."
2. Ron-Robert Zieler
Never given much of a look in at Manchester United, given the plethora of talented ‘keepers at the club during his Old Trafford days, Cologne-born star Zieler managed just two league appearances in England – and both of those came on loan at Northampton Town – before returning to Germany.
It’s been an entirely different story since, however, with the goalkeeper impressing enough with Hannover 96’s second team to earn a starting-spot for the Bundesliga side.
To date he has played almost 150 league games for the German outfit and recently earned a national team call-up, with five caps to his name to date.
"He got an injury here in the Reserves and was out for about eight months," Ferguson explained during an interview with the official Manchester United website on the topic of the player's new found success.
"Unfortunately, when he came back, Ben Amos had jumped ahead of him in the pecking order.”
1. Paul Pogba
Brought to England in controversial circumstances from Le Havre, who accused Manchester United of stealing their player (as reported by the Guardian), Pogba rarely got a look in for the first team.
All told, the 22-year-old managed just three Premier League appearances, along with three in the League Cup and one in Europe.
Since turning down a new contract to play for Juventus, the Frenchman has won a trio of Serie A titles, two Supercoppa Italias and the award for best young player at last summer’s World Cup.
But despite this, Gary Neville believes Ferguson was right to play hardball with the player, as he told Talksport in quotes republished by Squawka:
"He [Sir Alex Ferguson] would never give a young player too much too soon and there was a point whereby they made him a contract offer that they felt was a fair offer and Pogba wanted more."