West Ham fans will be surrounded by police following the last Olympiacos game being abandoned when an opposition player was struck by a firecracker.
The Greeks entertained Panathinaikos in a warm up at the weekend but the game between the old enemies was stopped as a visiting defender as struck while preparing for action as a possible sub and was taken to hospital.
A compulsory coach convoy with a police escort will be the only way into the stadium and it will meet n three hours before kick-off.
Athens police say the protocols must be observed warning that those not using them may be turned away.
UEFA have allowed Olympiacos and Panathinaikos to both play at home in the Europa League on Thursday, with the latter hosting Rennes approximately seven miles away.