Its above my paygrade mate but I've copied and pasted this from forbes - its written by a much smarter person than me lol..its all creative accountancy.. ...What also makes sense is the financials of the deal. On paper, Barcelona are said to be paying €70 million for Pjanic, while younger man Arthur is costing Juve €80 million, which looks to work out as a swap deal plus €10 million cash from the Bianconeri. However, FFP rules mean that both clubs will be able to report €60 million profit on their books, due to player amortisation.
Barca paid €30 million for Arthur in 2018 on a six-year deal, meaning that his value decreases by €5 million per year in terms of FFP. Therefore, he is now worth €20m in terms of their accounting, meaning a sale for the equivalent of €80 million means the Catalan side can show a €60 million profit.
Similarly, Pjanic arrived in Turin from Roma for €35 million in July 2016 on a five-year contract, meaning his FFP value reduces by €7m per year, leaving €21 million in value on the books after two years when he was handed a new five-year contract by the club. The remaining €21 million is then divided by five and therefore reduces by €4.2 million per year, and currently leaving €13 million in value on Juve’s accounts. A €70 million sale therefore leaves a tidy €57 million profit for the Old Lady