Wales' Williams out with shoulder injury
Scott Williams of Wales scores a try during the 2011 Rugby World Cup match against Namibia at Stadium Taranaki in New Plymouth on September 26, 2011 - by Peter Parks
The 23-year-old Scarlets back is set to undergo an operation on Thursday and could be out of action for as long as three months.
Williams came off worst from a thumping tackle on Ireland centre Brian O'Driscoll in the 17th minute of defending champions Wales' crushing 26-3 Six Nations loss in Dublin on Saturday
"Centre Scott Williams has been released from Wales' 2014 RBS 6 Nations squad due to injury," a WRU statement said.
"Williams injured his right shoulder in Saturday's defeat to Ireland and will require surgical intervention."
George North replaced Williams at centre during the match at Lansdowne Road game, with Liam Williams taking the giant flyer's place on the wing.
Wales coach Warren Gatland may be forced to stick with what appeared a temporary arrangement when Wales continue their Six Nations campaign against France at Cardiff's Millennium Stadium on February 21.
That is because centre Jonathan Davies looks likely to remain sidelined with the chest muscle problem he suffered during Wales' 24-15 defeat by South Africa in Cardiff in November.
"We are not too sure at the moment whether he (Davies) will be available against France," Gatland said Tuesday. "He is still not 100 percent.
"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," the New Zealander added. "He is not there at the moment, so he is not available at the moment."
Wales' bid for a record third successive outright Six Nations title is hanging by a thread, with a defeat by France all but certain to scupper their chances in a tournament where, thus far, an unconvincing opening win at home to Italy was followed by a heavy defeat in Dublin.