Jedinak, who is expected to captain the green and gold in Brazil, suffered a groin injury in the 59th minute of the 2-2 draw with relegated Fulham on Sunday.
The midfield enforcer will undergo scans this week to determine the extend of the problem, with Socceroos coach Ange Postecoglou due to announce his preliminary 30-man squad on Wednesday.
Palace finished the campaign in 11th place, while Fulham, by contrast, ended a depressing year second bottom.
Meanwhile, promising defender Trent Sainsbury’s hopes of being on the plane to Rio look all but over after he failed to recover from a freak accident on debut for PEC Zwolle in the Dutch topflight.
The 22-year-old former Central Coast has not played since fracturing his knee on a sprinkler in February.