CJ Stander's Six Nations Championship has been decimated after it was confirmed the back-row is out for four weeks out with a facial injury sustained in the defeat to England on Saturday.
The IRFU did not specify the exact nature of the injury, though his brother-in-law - South African swimmer Ryk Neethling - tweeted after the game: "Not the result we wanted but an incredible experience nonetheless and proud of CJ Stander playing 62 mins with two fractures in his cheek and eye socket."
Stander was replaced just after the hour mark by Sean O'Brien at the Aviva Stadium. He will definitely miss the games against Scotland and Italy, and faces a race against time to make the climactic showdowns with France [10 March] and Wales six days later.
It was a day to forget for the hosts, as Eddie Jones' pumped-up outfit barged their way to a deserved success.
A bruising contest took its toll on others in green. Keith Earls suffered a hip pointer injury and will be managed over the next couple of days, while Devin Toner aggravated an ankle injury and Garry Ringrose reportedly has a tight hamstring.
Both will be further assessed over the next 24 hours.
Andrew Conway suffered a tight calf in training last Thursday and will stay with Munster this week to continue his rehab.
Ireland go to Murrayfield on Saturday to take on the Scots, who opened their campaign with a 33-20 win against Italy.