Judgment of the Court (Grand Chamber) of 21 December 2023.#UL and SA Royal Antwerp Football Club v Union royale belge des sociétés de football association ASBL.#Reference for a preliminary ruling – Competition – Internal market – Rules introduced by international and national sports associations – Professional football – Private law entities vested with regulatory, control and sanctioning powers – Rules requiring professional football clubs to use a minimum number of ‘home-grown’ players – Article 101(1) TFEU – Decision by an association of undertakings adversely affecting competition – Concepts of anticompetitive ‘object’ and ‘effect’ – Exemption under Article 101(3) TFEU – Conditions – Article 45 TFEU – Indirect discrimination on the basis of nationality – Restriction on the freedom of movement for workers – Justification – Conditions – Burden of proof.#Case C-680/21.