The 21-year-old was close to a return after tearing his hamstring while playing for France at the European Under-21s Championship in June.
But Olise has re-injured his hamstring and will have to wait to return to action.
The setback is a major blow for Palace, who will continue to assess Olise over the coming days as they plot a new timeline for his return.
Olise signed a new four-year contract this summer, having been named Palace players’ player of the season after a club-record 11 assists last season.
His new deal has a release clause active in it from next summer, after Chelsea attempted sign him for around £35million at the end of the summer transfer window.