Reported as suffering from a 'chronic groin problem', Cooper may require surgery.
Australian Rugby League chief Geoff Carr stated that Cooper was considered as a possible replacement for Justin Hodges.
Hodges will undergo a shoulder reconstruction next month.
Officials have delayed naming a new replacement due to selector Bob Fulton - who is on a pig-shooting expedition in the Northern Territory - being out of contact range.
With Hodges and Cooper injured, and Mark Gasnier now playing rugby union in France, the call has gone out for Manly Sea Eagle grand final star Jamie Lyon to fill the void. But Lyon has in the past expressed a reluctance to play representative football.
In other injury news, Sea Eagles and Australian fullback Brett Stewart may also be ruled out after having a cortisone injection for a shoulder injury. Australian team doctor Hugh Hazard last night said Stewart was in doubt.