The move forms part of the deal which saw Bevan Fransman sign for Celtic as a replacement for Clayton Daniels, who signed a pre-contract with SuperSport.
Celtic coach Ernst Middendorp explains that Manzini is not in his plans for the season.
“To be honest, I feel that Manzini has fallen behind strikers like Trevor Lamola, Joel Mogorosi and Ghabadinho Mhango for a starting berth position,” he tells the club’s official website.
“Manzini is a big, physical striker and his style is a bit different to the one I foresee Celtic playing with this season.”