Moussa Wague is a former pupil of Aspire Academy, a Middle Eastern football school where he honed his skills from 2014 to 2016. His quality and level of performance with the junior categories of the Senegal national team saw him signed by KAS Eupen in November 2016. After 43 matches for the Belgian team, he joined Barça B in the summer of 2018, just after the World Cup. He became the youngest African to score in the competition, in Senegal’s game against Japan.

In that same season Wague began to make appearances for the first team. Coach Ernesto Valverde regularly included him in first team training sessions and he eventually made his debut in a league game against Huesca away from home. The defender made two more appearances for the first team against Celta and Eibar in the 2018/19 season before joining the first team squad ahead of the 2019/20 campaign. 

His excellent season led him to being included in the Senegal squad that was runner up in the 2019 Africa Cup of Nations.