Cian Healy is a doubt for Ireland's opening Six Nations game against Wales on 7 February after undergoing a knee operation on Tuesday.
The Leinster prop opted to have the surgery to coincide with his current two-week ban handed out for foul play in a recent game against Toulon.
A Leinster statement said Healy, 28, would be out for "three to four weeks".
"Cian Healy underwent a scope and clear-out of his right knee yesterday afternoon," added the statement.
The Leinster prop was ruled out for much of last season because of a neck injury but returned to action during the World Cup in the autumn.
Healy's fellow Leinster front row Mike Ross is expected to return in time for Ireland's Wales clash after being out of action over the past three weeks because of a hamstring tear.