Republic of Ireland manager Giovanni Trapattoni is to undergo minor abdominal surgery on Wednesday.
The Italian was admitted to hospital in Dublin with suspected food poisoning on Tuesday but it now appears his stomach condition has been caused by scar tissue from an earlier operation.
A statement from the Football Association of Ireland read: "Giovanni Trapattoni continues to have abdominal pain. Following the results of further investigation, and consultation with his surgeon, it has been decided the abdominal pain is as a result of minor scar tissue from previous surgery. To relieve the pain, he will undergo minor surgery."
Trapattoni arrived in Dublin on Sunday suffering with vomiting and nausea caused by suspected food poisoning from eating shellfish in Italy.
That resulted in the 71-year-old being taken to Dublin's Mater Hospital in the early hours of Tuesday morning where he remained overnight after undergoing a series of blood and urine tests, as well as x-rays and an ECG.
The FAI confirmed Trapattoni's progress throughout the night was "slightly behind expectations," resulting in further tests being conducted, and with a prognosis now finally being made.
It means Trapattoni will now be confined to watching Ireland's prestigious friendly against Argentina on television from his hospital bed.
Assistant-manager Marco Tardelli will take charge of the game, the Republic's first at their new home, the Â£350million, 50,000-seater Aviva Stadium.