The process of negotiations between Williams' agent and Barcelona executives started on June 13. The discussions continued on June 18 and 19, and eventually led to a meeting in Ibiza, where Barcelona's sporting director, Deco, met with Williams directly.

Although some sources suggested that Barcelona's coach, Hansi Flick, might have been involved in the meeting, it appears that Deco was the one who met with Williams. The two parties reached an agreement, which includes a contract that will last until 2031 and a yearly salary of €7-8 million.

Barcelona plans to pay the €58 million buyout clause to release Williams from his current contract, which is expected to happen next week.

It is worth noting that Williams' decision to leave Athletic Bilbao and join Barcelona has been communicated to the club's management, but the exact details of the transfer are still being worked out.