Ireland back Andrew Trimble will miss the remainder of the Six Nations with a hand injury sustained on Pro12 duty with Ulster.
Trimble was absent for Ireland's opening matches against Scotland and Italy as he recovered from a groin problem, before coming off the bench during last weekend's 19-9 victory over France in Dublin.
However, the 70-cap man picked up a problem in Friday's 19-7 win against Benetton Treviso, ending his involvement in Ireland's bid to regain the championship.
Lock Ultan Dillane, who has twice come off the bench during this year's competition, has been ruled out for up to 10 weeks due to surgery on a shoulder issue.
The experienced Tommy Bowe has been added to the squad, while Rob Kearney (groin) is expected to train fully on Monday.
Ireland sit second after three matches, three points behind leaders England, who visit Dublin on the final weekend after Joe Schmidt has taken his side to Wales.