United were recommended Frenkie de Jong and Matthijs de Ligt before they made their first-team debuts with Ajax, according to the club's former head of youth recruitment, Derek Langley.
The Dutch wonderkids have established themselves as two of football's hottest prospects since bursting onto the scene in 2016. De Jong is Barcelona-bound this summer after agreeing a transfer worth €86million in total, while De Ligt has also been linked with a big-money summer move to Europe's elite clubs.
De Jong was on Willem II's books before being snapped up by Ajax at 18 years of age while de Ligt broke into the Eredivisie giants' first team at just 16 - and went on to start the Europa League final against United.
Had United chiefs listened to Langley's recommendation, though, it could have been very different.
"Players that they turned down? Matthijs de Ligt. We had God knows how many reports on Matthijs de Ligt. Frenkie de Jong and all these players now are sort of around Europe," the 68-year-old told MEN Sport. "Dayot Upamecano, who is now at Red Bull Leipzig, was another.
"This was one of the reasons why I had a meeting with Ed Woodward and I told him that I wasn't convinced with the competency of certain people at the club. I told Ed Woodward quite straight: 'If you think I'm going to sit here and just tell you what you want to hear, I'm not that man because I'm going to tell you exactly how I see it'.
"I think it was possibly part of my downfall as to why seven months down the line I was removed because I wouldn't tow the line in relation to telling them exactly what I thought.
"It's one of them things in football - you come to accept it. Manchester United thanked me for the time I spent there and the players I'd taken in, but ultimately we could have been so much better if people had listened."
Langley, a lifelong United fan, spent 16 years as a talent spotter at Old Trafford, starting as a local recruitment officer then moving up to head of European recruitment and head of academy recruitment.
Marcus Rashford, Jesse Lingard, Gerard Pique, Danny Welbeck, Tom Cleverley, Giuseppe Rossi and Adnan Januzaj were among those who were scouted and signed on his watch between 2000 and 2016.
Gary Lineker wants Champions League rule change after Manchester United vs Barcelona
Remarkably, that was at a time when Langley had just two full-time scouts - one in South America and one in Europe - at his disposal. The rest were part-time.
It meant that United's head of youth recruitment was constantly travelling the world covering youth tournaments. Not only looking at potential targets but, also, handling matters as trivial as schoolboys' expenses at the same time.
United's local network suffered as a result at a time when Man City were ploughing millions into their academy, scouting network and infrastructure following Sheikh Mansour's takeover.
Langley appealed for help but it was only after his departure that United's scouting network in Europe, South America and Asia trebled in size. Indeed, the club now have more than 50 scouts on their books.
Real Madrid midfielder Casemiro talks up Paul Pogba transfer from Manchester United
But his legacy lives on in the shape of the club's hottest prospect - Tahith Chong.
"Tahith was spotted when he was 14/15-year-old playing in a tournament at Carrington. What used to be the Nike Premier Cup," he added. "He had already been tipped by our scouts in Holland and basically I followed him at that tournament and then I followed him all over Europe.
"Tahith's parents would be the first to tell you that his form dipped slightly due to growth issues so at that time I just held fire. I carried on watching him and realised his form was coming back.
"He was on the verge of signing for Chelsea and I managed to convince his parents and the boy his future lied at United."
*This interview was originally published in December 2018.
Romelu Lukaku warns his Manchester United teammates over Barcelona second leg
