The team made the announcement less than an hour before their season-opening media day began.
Koloko will not participate in the Raptors training camp in Vancouver.
The 23-year-old Koloko missed summer league play with the same condition.
Koloko was selected by Toronto in the second round, 33rd overall, of the 2022 NBA draft.
He averaged 3.1 points, 2.9 rebounds and 0.5 assists per game last season.
This report by The Canadian Press was first published Oct. 2, 2023.
The Canadian Press