Adama Boiro has played 45 times for Athletic Club, including six appearances in last season’s Champions League. Boiro's arrival was late due to a delayed flight on deadline day and his deal was processed at the last minute. The BBC.co.uk web site reported his arrival on a loan with an option to buy.

Nuno Espírito Santo and Nils Koppen expressed satisfaction with the signing of Adama Borio, stating that he is a player they have followed closely and believe will fit well into the group structure. Adama Borio expressed excitement and happiness about joining West Ham. He called the club great and is looking forward to working with his new teammates.

Athletic Club and West Ham United officially announced after 1 AM that they have reached an agreement for the loan of 24-year-old Spanish-Senegalese left-back Adama Boiro to the English club until the end of the season. The player, who is under contract with Athletic until June 30, 2029, is already in London to sign with the club. The loan agreement includes an option to buy. According to Transfermarkt, his current market value is €2.50m.