Ireland fly-half Jonathan Sexton is facing two weeks out of action after suffering a hamstring injury during his side's defeat to England on Sunday.
The 27-year-old was withdrawn in the first half as the Red Rose went on to record a 12-6 win at the Aviva Stadium and move to the top of the Six Nations table.
Sexton is now a doubt for Ireland's trip to Scotland later this month, although coach Declan Kidney is not sure exactly how long a lay-off he will endure.
"It looks like a couple of weeks for Jonny, but it would be wrong to try to second-guess the outcome. We'll know more by Tuesday," said Kidney.
"It's been an additional couple of games and we had a few injuries leading into the tournament, but that's the way it goes."
Ireland are already without Simon Zebo, who will miss the rest of the competition with a broken foot.
