Wales centre Scott Williams will miss the rest of the Six Nations due to a shoulder injury picked up in the 26-3 defeat by Ireland at the weekend.
Williams, 23, was forced off the pitch early in the first half of the match in Dublin after making a heavy tackle on Brian O'Driscoll, who also needed treatment but remained on the field.
The injury requires surgery, ruling him out of the remainder of the tournament.
Fellow centre Jonathan Davies faces a battle to regain his fitness for Wales' next match against France in Cardiff on 21st February.
No signigicant improvement
He is coming back from a pectoral injury suffered against South Africa in early November but coach Warren Gatland said he needed to show significant improvement to be considered for selection.
"He has been re-scanned. He is still a little bit sore at the moment," Gatland revealed.
"He played that game for the Scarlets last week and felt a little bit sore, so we are trying to assess him to get up to speed in terms of lifting weights and contact. He is not there at the moment, so he is not available."
Wales are bidding to become the first team to win three consecutive Six Nations titles outright.
They beat Italy in their first match before being comprehensively beaten by the Irish.