The sentencing proceedings of former Parktown Boys High water polo coach Collen Rex are expected to begin on Thursday in the South Gauteng High Court, sitting in Palmridge, east of Johannesburg.
Arguments in mitigation and aggravation of sentence will be heard.
Rex was found guilty last week of assaulting and sexually assaulting a number of boys at the school where he worked.
The court found Rex guilty of 144 charges of sexual offenses as well as 12 charges of common assault.
The case was postponed on Monday due to an outstanding victim impact report from the social worker.
The 22-year old was initially facing more than 300 charges including rape, exposing minors to pornographic material and attempted murder, all relating to the sexual abuse of 23 children at the school where he worked as a sports coach.