Garry Ringrose is facing up to five months on the sidelines after having an operation on his shoulder.
Leinster have confirmed the centre went under the knife last Monday and is facing a lengthy stint of rehabilitation.
Ringrose played all three Tests on Ireland's summer tour to the US and Japan, scoring two tries.
The 22-year-old now has a battle to return to action before Christmas.
A Leinster statement read: "Leinster Rugby can confirm that Garry Ringrose underwent an operation last Monday.
"The operation to address an ongoing shoulder issue was successful but Ringrose will be out for 4-5 months, depending on his rehabilitation.
Ringrose started in all three of Ireland’s summer tour fixtures against USA and Japan, scoring two tries and kicking one conversion.
The operation to address an ongoing shoulder issue was successful but Ringrose will be out for 4-5 months, depending on his rehabilitation.
