Sean O'Brien will miss Ireland's crucial trip to Twickenham when the Six Nations resumes in a fortnight, head coach Joe Schmidt has confirmed.
The flanker suffered a grade two hamstring tear in last Saturday's narrow defeat by France, which saw a number of Irish stars leave the field on a brutal afternoon in Paris.
"Sean O'Brien, unfortunately he's got a Grade Two hamstring tear so that will make him unavailable for the England game," Schmidt said. "We'll see how he tracks beyond that."
Dave Kearney was another casualty at the Stade de France, picking up a shoulder injury after what appeared to be a high tackle from French captain Guilhem Guirado.
The wing is a doubt for the clash with England, while Ireland are also concerned about the fitness of Mike McCarthy after the lock sustained a concussion in the second half in Paris.
"Mike McCarthy obviously suffered concussion and he will follow the return to play protocols," Schmidt said. "We'll also get him to see a specialist, just because the nature of the impact."
However, there was more positive news regarding talisman Johnny Sexton, with Schmidt saying the fly-half was recovering well from the "whiplash" he suffered against France.
"You've got Jonathan Sexton, again his neck and shoulder," Schmidt added. "It's more of a whiplash injury but he is certainly feeling a lot better 48 hours post-match."