Ireland prop Andrew Porter will miss the remainder of the Six Nations with an ankle injury.
The Leinster player hobbled off early in the second half of Ireland's 57-6 victory over Italy in Dublin on Sunday.
Porter will now sit out the clashes with England at Twickenham on March 12 and Scotland at the Aviva Stadium on March 19, with Leinster team-mate Cian Healy and Munster's Dave Kilcoyne in contention to take his place.
The Irish Rugby Football Union has confirmed Porter will return to his province for medical treatment following the results of his scan.
The 26-year-old has been a key component of Andy Farrell's side, successfully switching from tighthead to loosehead this season.
Porter's fellow front rower, Ronan Kelleher, is also out of the Six Nations having suffered a shoulder injury during the 30-24 defeat to Grand Slam-chasing France in round two.
Ireland - who began their Six Nations campaign with a 29-7 victory at home to Wales - sit second in the standings after three rounds, three points behind leaders France.