Wales wing Shane Williams looks to have played his final RBS 6 Nations game after being ruled out of Saturday's clash against France in Paris.
Williams, 34, has maintained he will retire from Test rugby following the World Cup in New Zealand later this year.
But Wales' record international try-scorer will not be involved this weekend due to a knee injury suffered during the 19-13 victory over Ireland four days ago.
He is expected to be sidelined for six to eight weeks with posterior cruciate ligament damage, although he will not require surgery.
Williams' replacement in the starting line-up for Paris, which Wales coach Warren Gatland will announce tomorrow, is expected to be teenager George North or Morgan Stoddart.
If 18-year-old North is preferred, then it will be his first Six Nations Test. He scored two tries on debut against world champions South Africa in November, but has only recently returned to action following a shoulder injury.
Williams' absence is a major blow for Gatland, with Wales still holding an outside chance of the Six Nations title, although they need to beat France, rely on Ireland to defeat England and see a points swing of more than 40.
"Shane will be out of action for a period of six to eight weeks after sustaining damage to the posterior cruciate ligament in his left knee during the match at the weekend," said Prav Mathema, Wales' medical manager.
"Thankfully there is no need for surgical intervention, and he will now undergo a period of rehabilitation which will see him return to full fitness."
After this weekend, Wales' next fixture is against the Barbarians in Cardiff on June 4 before World Cup warm-up appointments with England (twice) and Argentina in August.
Wales forwards coach Robin McBryde, meanwhile, believes Ireland are capable of destroying England's Grand Slam dream.
England's first championship clean sweep since 2003 hinges on them winning at Dublin's Aviva Stadium in a game that will finish before Wales kick off at Stade de France.
McBryde said: "We believe Ireland have got the capability of beating England, and who knows with France what to expect? All we can do is focus on what we can control.
"Ireland will be a little bit frustrated after last weekend, and I think they have got enough in their armoury to cope with England, but England have momentum.
"It will be quite close - anybody's victory on the day."