The Blades have brought Mali under 20s midfielder Ismaila Coulibaly onto the books from Norwegian side Sarpsborg 08.
However, Coulibaly has been immediately sent to Belgian side Beerschot, with whom United have strong links.
In 2018 it was revealed that Blades owner Prince Abdullah had invested in Beerschot.
Coulibaly, 19, has made 28 league and cup appearances for Sarpsborg 08, scoring four goals.
A statement on the Blades website about the move read: “Beerschot have recently been promoted to the Belgian top flight and the Blades will monitor Coulibaly's development whilst playing for the Antwerp-based outfit.
"Through mutual management, United have an excellent working relationship with K Beerschot VA which could develop with further partnerships going forward.”