Ireland flanker David Wallace was ruled of the Rugby World Cup after damaging his knee in the 20-9 loss to England at Lansdowne Road on Saturday.
Wallace's right knee was twisted in a tackle by Manu Tuilagi midway through the first half, and he was carted off in obvious pain.
"David took a very bad bang on the knee and while we don't know the exact prognosis, he has unfortunately been ruled out of the World Cup," Ireland coach Declan Kidney said.
Wallace, capped 72 times since 2000, was preparing for his second World Cup.
"David took the news like the man he is," he said. "You have to deal with these things. He's 35 and I've never seen a man as physically fit as he is right now. Never.
"It's heartbreaking for him and his family. It's extremely disappointing for us and will be good news for someone else. That's the cut-throat nature of sport."
Kidney expected the others who left the game early - Cian Healy (eye), Jerry Flannery (shin), Stephen Ferris (hand) and Jamie Heaslip (concussion) - to be available for the World Cup opener on September 11 against the United States.