Adrián Diéguez had strongly advocated for a transfer to CSKA Sofia in the past. Jagiellonia Białystok attempted to manage the situation by signing a new contract with him, despite his behavioral challenges. Recently, the club contemplated ending his contract due to his lack of dedication and dissatisfaction with his exclusion from the starting lineup. Diéguez's discontent intensified during a match against FK Novi Pazar in the UEFA Europa Conference League qualifiers, where he left the bench without permission upon discovering that he would not participate, leading the staff to step in. The growing tensions between Diéguez and Jagiellonia Białystok resulted in the club deciding to part ways with him, facilitating his move to CSKA Sofia. His contract with Jagiellonia, which had been extended in November to last until June 30, 2026, was criticized by sports analysts as a mistake, as the club now searches for a suitable replacement.