Ghana's Group B opponents Mali will miss the services of Lille midfielder Adama Traore for the 2015 African Youth Championship in Senegal.
His French Ligue 1 side refused to release him for the two-week tournament which starts on Sunday.
Les Aiglons coach Fagnéry Diarra had included the 19-year-old in his provisional 22-man squad which includes nine foreign-based players.
Traore is a promising prospect who made his Ligue 1 debut at 24 September 2014 against OGC Nice in a 1-0 away defeat.
On 7 Janaury this year, he scored his first goal at senior side of Lille against Evian TG in the Ligue 1.
Mali open their campaign against Zambia on 19 January before facing South Africa and Ghana.
Mali U20 final squad:
Goalkeepers: Djigui Diarra (Stade Malien), Sory Ibrahima Traoré (ASB), Mahamane Baye (Avenir Tombouctou)
Defenders: Youssouf Koné (Lille/FRA), Bourama Doumbia (ASPIRE/SEN), Souleymane Coulibaly (AS Réal), Hamidou Maïga (LCBA), Aboubacar Doumbia (AS Réal), Ichaka Diarra (Stade Malien)
Midfielders: Diadié Samassékou (AS Réal), Souleymane Diarra (WAC/MAR), Falaye Sacko (Djoliba AC), Alassane Diallo (Westerlo/BEL), Moussa Bagayoko (Black Stars), Fousseyni Diabaté (Rems/FRA), Moussa Sissoko (AS Police),
Strikers: Hamidou Traoré (Elagizspor/TUR), Mohamed Guilavogui (Montpellier/FRA), Saliou Guindo (ASEC Mimosas/RCI), Malick Touré (Club Africain/TUN), Souleymane Sissoko (Onze Créateurs)