A month ago, Barcelona were tipped for the treble and an all Cruyff final, i.e, Barcelona vs Ajax was dreamt of. But a humiliating 4-0 defeat in the second leg of Champions League semi-final vs Liverpool and a 2-1 loss to Valencia to the Copa del Rey final meant Barcelona ended the season with just the La Liga title when for the entirety of the season they were the fore-runners in all 3 competitions.Hence, the Champions League elimination and Copa del Rey disgrace have brought about a chain of events that even the Barcelona board has struggled to deal with. There are serious doubts over the future of a number of players. There are also doubts whether, Ernesto Valverde, will continue or not. Also, a number of players have been linked with the club in recent weeks who are tipped to join, in the coming weeks.This has led to a complex summer transfer opera for the club. We look at the events that have caused it.#4 Neymar-Dembele swapNeymar left Barcelona for PSG in 2017 summer for a world record fee of €222 millionAccording to Catalan media, Barcelona and PSG are going to begin talks for the return of Neymar to the club. It also states that Dembele will be a part of the deal which will also involve a fee in the region of €120 million. Still, the Catalan media have had its hits and miss when it comes to transfer rumours and can't be relied upon.But, a few days earlier, Esporte Interativo came in stating that Neymar believes that his PSG departure this summer is on the cards. The source suggests that there is a 'very real possibility' that the forward will return to Barcelona.It also stated some big points, the positive and negatives. Apparently, the player still believes that the club owes him €26 million as his loyalty bonus which the club are reluctant to pay. The player is also likely to ask for a salary of around €30 million which the club obviously cannot afford. Also, the core players of the team want to see the player back at the club and fully back the move. What's more, this news comes from Marcelo Bechler, a journalist who first reported about Neymar's future transfer to PSG in 2017. Gerard Romero, a highly reliable source for Barcelona-related information, has also reported the club have been in talks with PSG over a potential Dembele for Neymar swap deal.Daily Record's Duncan Castles also suggested that Philippe Coutinho could also become part of the deal. It must be noted both Dembele and Coutinho have been PSG's targets before joining Barcelona.