Mngqibisa only played five games in all competitions this season and came under fire for his performances from some of the club's fans. He initially linked up with Usuthu in August 2016 after leaving University of Pretoria.
Fellow defender Moerane joined AmaZulu at the same time after leaving Bidvest Wits, but failed to play a single game for the Durban-based outfit.
The 22-year-old was part of Owen da Gama's squad at the 2016 Olympic Games where he featured once against Denmark in the group stages.
“We’ve terminated the contracts of Tebogo Moerane... the left-back, as well Vukile Mngqibisa,” confirmed Usuthu general manager Lunga Sokhela.
AmaZulu recently signed Sbusiso Mabaliso from Platinum Stars to provide competition at left-back for Simphiwe Mtsweni.
Cavin Johnson's side have also loaned Sibusiso Magaqa to Uthongathi FC, Skhumbuzo Mazibuko to Real Kings and Nkanyiso Zungu to Jomo Cosmos.