Bissouma signed a contract with Ajax in mid-September, following the expiration of his contract with Tottenham Hotspur in the summer. He made his debut as an invaller for Ajax against FC Groningen, but due to signing his contract after the Conference League registration deadline, he may only be able to feature in European competition for Ajax if the team progresses to the next round. VoetbalPrimeur reports that Bissouma has been waiting for his Ajax teammates in the Johan Cruijff ArenA catacombs after their 2-0 win over Atalanta, where he greeted Abdellah Ouazane with a warm welcome, calling him "Lamine Yamal".