Ireland wing Simon Zebo will be sidelined for 10 weeks after breaking a bone in his foot during the 12-6 defeat to England in Dublin.
The 22-year-old Munster star was forced off in the 10th minute at the Aviva Stadium and will undergo an operation on Monday, ruling him out of the remainder of Ireland's Six Nations campaign and possibly Munster's Heineken Cup quarter-final away to English champions Harlequins on April 7.
Ireland coach Declan Kidney said afterwards: "Simon will have surgery tomorrow. It's been an attritional couple of games and we had a few injuries leading into the tournament, but that's the way it goes."
Zebo, who can also operate at full-back, has enjoyed a rapid rise to prominence since making his Munster debut in 2010 - and some were confident that a solid Six Nations would see him enter the reckoning for British & Irish Lions selection.
There was a lengthy casualty list for Kidney to contend with in the wake of a brutal game - with Jonathan Sexton, Sean O'Brien (both hamstring), Mike McCarthy (knee ligament strain), Brian O'Driscoll (twisted ankle) and Donnacha Ryan (back) all hurt.
Sexton, who many feel will beat Owen Farrell to the Lions' 10 jersey, appeared to have torn a muscle as he hobbled off - but Kidney is cautiously optimistic the Leinster fly-half will be in contention for the trip to Scotland in two weeks' time.
"Jonny will have a scan either later tonight or tomorrow," Kidney added. "It looks like a couple of weeks for Jonny, but it would be wrong to try and second guess the outcome. We'll know more by Tuesday."
On the defeat itself, Kidney said: "This gives England a bit of daylight with the other five side on two points each with three matches to play.
"We're extremely disappointed because that wasn't the result we wanted. Let's see what France come up with at Twickenham. England have to go to Cardiff too.
"There's still a hell of a lot to play for. What we have now are three more opportunities to get three wins. Let's get to eight points and see where we are at the end of it.
"The Grand Slam is a wonderful thing to win, but first and foremost you play for the championship and we're still well in for that."