Sir Alex Ferguson established himself as one of English football's greatest-ever managers during his legendary reign at Manchester United - but even the iconic Scotsman didn't get everything right.
Amid the scrutiny of United's recent transfer business, it's widely acknowledged that the club have struggled on all fronts since Ferguson stepped down back in 2013, including recruitment. Many feel that United overpay for players, while several signings of Erik ten Hag - the man currently at the helm - have massively underwhelmed.
With that in mind, Mirror Football has taken a look at the most expensive players Ferguson signed during his 27-year tenure. And while there are plenty of blockbuster names on the list, not all of them were a hit...
10. Antonio Valencia - £16million
Valencia, a versatile Ecuador international, was snapped up after impressing Ferguson at Wigan Athletic. While £16m may seem a fairly modest transfer fee in this day and age, at the time, it was a fairly big sum to pay.
With that being said, Valencia proved to be exceptional value for the money. He spent a decade at Old Trafford and played over 300 times initially as a right winger before being converted to a right-back. Valencia even captained the side under Jose Mourinho before eventually moving abroad in 2019.
Premier League odds and betting tips9. Owen Hargreaves - £17million
Hargreaves was signed for a similar amount of money a couple of years prior to Valencia's arrival at Old Trafford, but the England international struggled to hit the same heights.
The Canada-born midfielder was plagued by injuries throughout his career and his time in the Premier League was no different, with the Hargreaves making just 39 appearances across a four-year period for the Red Devils. Intriguingly, he briefly joined Manchester City after leaving United but played just one Premier League match before being released.
8. Michael Carrick - £18.6million
Carrick arrived at Manchester United with a reputation as one of England's finest technical midfielders - and he certainly lived up to the hype.
The former West Ham and Tottenham star grew as a player over the years after joining in 2006 and even became club captain in the latter stages of his career. Carrick won five Premier League titles at United and the Champions League before hanging up his boots after 12 trophy-laden years in Manchester.
7. David de Gea - £18.9million
De Gea would go on to become an iconic goalkeeper for Manchester United after being signed by Ferguson in 2011 - but it certainly didn't feel like he would during his calamitous early days at the club.
The Spaniard would make 545 appearances in total for the club before departing in the summer and establishing himself as one of the Premier League's finest goalkeepers during his peak years. When it comes to value for money, few on his list can match the longevity and success of De Gea.
6. Ruud van Nistelrooy - £19million
Van Nistelrooy was, quite frankly, nothing short of an imperious goal machine. The fact that he will go down in club history as one of United's best-ever strikes speaks volumes despite his relatively brief stint at Old Trafford.
The deadly Dutchman plundered 150 goals in 219 games across a five-year period - not bad for £19m, even if that was a hugely significant amount of money at the time.
5. Robin van Persie - £24million
Pinching Van Persie from Arsenal may have been one of United's most controversial signings during the Fergie era, but it was also one of the most fruitful.
Just like his compatriot at No.6, Van Persie was a roaring success at Old Trafford and made an instant impact by firing his new team to the Premier League title shortly after joining.
World Cup hero wants Man Utd move as doubts over Harry Maguire's future growAfter scoring 30 goals in his maiden season, Van Persie would continue to lead the line for United for another two years before moving overseas with Fenerbahce.
4. Wayne Rooney - £27million
Rooney was one of English football's hottest prospects when he joined United for a whopping £27m fee from his boyhood club, Everton.
The England star became United's all-time leading goalscorer during his 13-year stay at Old Trafford, netting 253 goals in 559 appearances to eclipse all those who had come before him at the Theatre of Dreams.
A return to Goodison Park beckoned during his twilight years, but Rooney left the club a bonafide legend and proved to be one of the club's best pound-for-pound signings ever.
3. Juan Sebastian Veron - £28million
While Rooney and others should steal the plaudits on this list, the £28m deal to bring Veron to United is still a tough one to swallow. The midfielder became England's most expensive player back in 2001 but failed to live up to expectations during his time at the club. Having failed to replicate the dazzling form he showcased in Italy, Veron is still widely acknowledged as Ferguson's biggest blunder when it comes to transfer dealings.
2. Rio Ferdinand - £30million
Ferdinand became both the most expensive defender in the world and the most expensive British football player in history when he crossed the divide from United's bitter rivals, Leeds in 2002.
It was money well spent, though, with Ferdinand going on to establish himself as one of the finest defenders of his generation. He spent 12 years at Old Trafford and made over 450 appearances before moving back to London to see out his career.
Ferdinand's imperious partnership with Nemanja Vidic was the platform that enabled United to win the 2008 Champions League and numerous other trophies during some of the best years of Ferguson's lengthy reign.
1. Dimitar Berbatov - £31million
Everyone remembers that clip of Berbatov and Ferguson walking through the corridors of Old Trafford on Sky Sports News, but perhaps not everyone is aware that, at £31m, the striker is Fergie's most expensive ever signing.
The Bulgarian forward was a big hit at Tottenham and was eventually prised away to add to United's firepower. He scored 56 goals in 149 appearances for the Red Devils before moving back to the capital with Fulham.