Over the last ten years, the Red Devils have forked out over £1billion on transfer fees.
In fact, United are second to only Chelsea in terms of the most spent on transfers in the last five years.
Yet the large investments into the playing squad have largely failed to transform the club's fortunes on the pitch.
It has come to a head this season as United are on course for their lowest-ever finish in the Premier League era having come eighth in what was an all-time Premier League low last season.
Although a multitude of factors across the board have contributed to the Red Devils' demise, the level of quality amongst the players and the transfer fees attached are two of the biggest according to Ratcliffe.
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In an interview with the BBC, Ratcliffe pointed out such were the high fees for five players, United will only fully pay off their transfers this summer.
Ratcliffe name-dropped Rasmus Hojlund, Andre Onana, Casemiro, Jadon Sancho and Antony as 'players we are buying this summer, that we didn't buy'.
"These are all things from the past, whether we like it or not, we've inherited those things and have to sort that out," Ratcliffe said.
"For Sancho, who now plays for Chelsea and we pay half his wages, we're paying £17million to buy him in the summer."
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When pressed whether he had suggested the five players named weren't good enough for United, Ratcliffe replied: "Some are not good enough and some probably are overpaid, but for us to mould the squad that we are fully responsible for, and accountable for, will take time.
"We've got this period of transformation where we move from the past to the future.
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"There are some great players in the squad as we know, the captain is a fabulous footballer.
"We definitely need Bruno (Fernandes), he's a fantastic footballer."
With United's many financial missteps in the transfer market in previous years, it makes manager Ruben Amorim's job to improve their fortunes on the park that much harder.
Amorim, who has lost eight of his 17 Premier League matches in charge, was only able to sign one player of his choosing in the January window.
That was left-back Patrick Dorgu, who joined from Serie A side Lecce for upwards of £29m.
Given Ratcliffe's claims about the state of the squad, it explains why he's given Amorim a pass mark in terms of his results since taking over last November.
"If I actually look at the squad which is available to Ruben, I think he is doing a really good job to be honest," Ratcliffe said.
"I think Ruben is an outstanding young manager. I really do.
"He's an excellent manager and I think he will be there for a long time."
The contest is evenly poised at 1-1 following the first leg in San Sebastian.