Fitzgerald is expected to be out for six weeks while a date for Kearney’s return has yet to be set.

Doubts also hang over the participation of Brian O'Driscoll, Tommy Bowe and Gordon D'Arcy against the Pumas.

O’Driscoll has a bruised shoulder while Bowe and D’Arcy have calf strains with an update on the trio’s availability expected on Tuesday.

“All three will undergo rest and rehabilitation on their injuries but at this point have not been ruled out against Argentina,” read a statement issued by Ireland.

The conclusion of Rory Best’s autumn came last night after he sustained a fractured cheekbone.

The Ulster hooker will undergo surgery tomorrow and is expected to remain in the treatment room for six weeks.

Ireland yesterday produced their best performance of the November internationals by some margin, but it has come at a cost.

Should O’Driscoll, D’Arcy and Bowe fail to recover, coach Declan Kidney will be missing his entire first-choice three-quarter line outside of the half backs for Argentina.

It is a bitter blow for Fitzgerald, who made his Test return against South Africa at the start of the month following a year’s absence because of a knee problem.

“Luke suffered a medial ligament injury to his left knee,” read the statement.

“The damage is to the same knee that he injured last November, but this is a new injury and to a different part of the knee.

“Rob Kearney also injured his knee and has suffered cartilage damage.

“He will undergo exploratory surgery this week to further determine the extent of the injury and the period of recovery that he will need, but is certainly ruled out of the game against Argentina.”