Ireland centre Gordon D'Arcy will miss the rest of this season's RBS 6 Nations Championship due to a foot injury.
The Leinster player is likely to be sidelined for six weeks, the Irish Rugby Football Union announced.
Ireland have already lost wing Simon Zebo (foot) for the rest of the tournament, while fly-half Jonathan Sexton (hamstring) and lock Mike McCarthy (knee ligament strain) will also miss the game against Scotland at Murrayfield on February 24.
D'Arcy experienced discomfort in his right foot following the 12-6 defeat against England in Dublin last Sunday.
"This failed to settle down before the Ireland training session on Thursday, and following a scan yesterday afternoon it was confirmed that D'Arcy has a stress injury to a bone in his foot," the IRFU said in a statement.
"The injury will require immobilisation in a boot for at least four weeks, with a projected return to play of six weeks, pending further tests and specialist review.
"The Ireland training squad for the Scotland Test match will be announced on Sunday evening following the completion of games in the RaboDirect Pro12."
D'Arcy's injury means that Ireland coach Declan Kidney will need to make at least five changes for the trip to Edinburgh.
On top of the injuries to D'Arcy, Zebo, Sexton and McCarthy, prop Cian Healy is suspended after he was cited for stamping on England prop Dan Cole at the Aviva Stadium.
Ireland currently lie fourth in the Six Nations table with one win from two games. After the Scotland fixture, they host France on March 9 and then tackle Italy in Rome seven days later.