Chelsea may have pulled off one of the better pieces of transfer business of the summer according to people within the club.

Manchester United spent £50million to prise Andrey Santos away from Stamford Bridge, believing they had secured a midfielder with enormous potential.

However, just a few months into his Old Trafford career, questions are already being asked about whether the Brazilian was worth that kind of money.

Chelsea insiders believe Man United overpaid for Andrey Santos

The Athletic's latest report on Manchester United's recruitment under Jason Wilcox has revealed that some people within Chelsea believe United paid around £25million more than what Santos is worth.

The midfielder joined the Red Devils in a deal worth £50million, consisting of £48million guaranteed and a further £2million in add-ons. Chelsea also negotiated a 10 per cent sell-on clause, meaning they could benefit again if United eventually sell him.

Santos had shown plenty of promise during his time at Chelsea, registering three goals and five assists in 47 appearances across all competitions. However, the club were prepared to let him leave, and United were willing to pay a significant fee to bring him to Old Trafford.

The Athletic's report also raises questions about whether Santos was the right profile for United's midfield. His mobility alongside Youri Tielemans is at odds with what the club needed from its recruitment.

Chelsea could be laughing all the way to the bank

There is an argument that Chelsea have come out of this transfer rather well.

Santos is only 22 and has plenty of time to develop, so it would be premature to write him off after a relatively short spell at Old Trafford. 

However, his involvement has been limited, with the Brazilian making just four Premier League starts since joining United.

He has also struggled to establish himself as an automatic starter, raising questions about whether Michael Carrick is entirely convinced by his new midfielder.

For Chelsea, the situation is different. They managed to get a massive fee for a player who was not guaranteed a regular starting place, while retaining a sell-on percentage that could prove valuable in the future.

United, meanwhile, need their expensive midfield recruits to start justifying the money spent on them. Spending £50million on a player is one thing, but spending that amount on someone who does not immediately improve the starting XI is another. Just the latest example of the mess at Manchester United.

Santos still has time to prove his doubters wrong, and Chelsea will not be complaining if he eventually becomes a success at Old Trafford. After all, the better he performs, the more valuable that sell-on clause could become.

But for now, the verdict from people close to Stamford Bridge suggests Chelsea have secured a much better deal than their Premier League rivals.