Scans have revealed Panthers fullback Jarome Luai suffered a syndesmosis injury in his left ankle during Friday's defeat to Brisbane Broncos.
The 21-year-old will review with a specialist next week and will be sidelined indefinitely.
Luai's replacement to face Manly will be revealed when Panthers coach Anthony Griffin names his side on Tuesday.
It is hoped Dallin Watene-Zelezniak will be fit to return from a hamstring injury while rookie Caleb Aekins is also in contention for selection.
