With Nemanja Vidic announcing his intention to leave Manchester United, an added focus is likely to be taken on central defensive recruitments this summer.
One of the most in-demand centre-backs in European football is Eliaquim Mangala of Porto, who was linked with a deadline day switch to Manchester City.
The Frenchman is expected to leave the club this summer, but new light is being shed on why his deadline day switch did not materialise.
French website Le10Sport claims City's offer fell short of what Porto were asking, as they tried to accomplish a double deal to sign midfielder Fernando.
"The Portuguese club was indeed surprised to receive a formal proposal of Manchester City less than 10 million euros to what was originally planned!
"While it was agreed for everyone that FC Porto will let go Eliaquim Mangala the amount of his release clause, namely €46 million, Manchester City has finally faxed an offer of €36 million in the last hours in the winter transfer window. The proposal was rejected by FC Porto."
Whether City's offer was simply a miscommunication, or to do with Financial Fair Play and not wanting to pay over the odds, we may never know, but it certainly opens up Mangala's future to be a much-debated point ahead of the summer.
Le10 report that French giants PSG and AS Monaco are interested, with Alex planning to depart the champions in the summer.
Mangala has never played in his homeland, and should he feature at the World Cup his stock will only rise.
Monaco also struck deals with Porto last summer for Joao Moutinho and James Rodriguez, and it would be no surprise to see the big spenders move to beat their rivals to the punch.
Also likely to be interested of course now, are Manchester United, needing a replacement for Nemanja Vidic to lead the team forward. City's failure to do the deal has now opened up a chance, but their likely inability to offer Champions League football could just be the turning point.