​Karim Adeyemi’s move to Barcelona is set to become official after one of the fastest transfer negotiations of the summer, with the entire operation completed in under three days.According to BILD (h/t SPORT), the deal came together through a combination of decisive action from Barça sporting director Deco, the influence of agent Jorge Mendes and the player’s own determination to join the Catalan club.AdvertisementAdvertisementAdvertisementThe transfer process began when Barcelona formally informed Borussia Dortmund of their interest in Adeyemi. Deco personally contacted Dortmund chief executive Lars Ricken and sporting director Sebastian Kehl to open negotiations.The German club were already aware that the winger intended to leave, having been informed by Jorge Mendes after Adeyemi repeatedly declined offers to extend his contract, which was entering its final year.Barcelona’s opening proposal was worth €20 million in fixed payments. The Catalan club believed their offer reflected the player’s contractual situation and made it clear they would not enter a bidding war.Dortmund rejected Barcelona’s opening offer. (Photo by Pau Barrena/Getty Images)AdvertisementAdvertisementAdvertisementBorussia Dortmund rejected the initial proposal but outlined their position.Rather than seeking to make a profit, the Bundesliga club simply wanted to recover the investment they had made when signing Adeyemi from Red Bull Salzburg. Their valuation stood at approximately €31 million.Following this, negotiations briefly reached a standstill. At that point, Adeyemi personally intervened.The German international called Dortmund directly to make it clear that Barcelona was his only preferred destination and that he had no intention of considering offers from any other club.AdvertisementAdvertisementAdvertisementAt the time, the winger was spending a short holiday in the United States. His message to Dortmund significantly increased the pressure to find an agreement.With Jorge Mendes acting as intermediary, Deco quickly returned with an improved proposal just 24 hours later.Barcelona increased the guaranteed transfer fee to €22 million and added performance-related bonuses that could take the total package considerably higher.Adeyemi’s call to Dortmund was the clincher. (Photo by Fabio Deinert/Getty Images)Many of those bonuses are linked to team achievements and are viewed by Dortmund as highly achievable. Barcelona also informed the German club that the revised proposal was final.AdvertisementAdvertisementAdvertisementThe alternative, they argued, would be risking Adeyemi leaving as a free agent once his contract expired.Faced with that scenario, the Bundesliga club gave their verbal approval, allowing lawyers from both clubs to begin preparing the official paperwork.The agreement also includes a significant percentage of any future transfer, although Dortmund accept that clause may never generate substantial income if Adeyemi establishes himself succ