Lions flankers Colin Charvis and Martyn Williams look certain to miss an eagerly-awaited appointment with the world champions on February 5, and their chances of facing Italy in Rome seven days later also appear bleak.

Wales vice-captain Charvis is suffering from ligament damage in his right foot, while Williams has a disc-related neck problem.

Wales coach Mike Ruddock has called uncapped Neath-Swansea Ospreys flanker Richie Pugh into his RBS 6 Nations squad, and Cardiffs Robin Sowden-Taylor will provide training cover for Williams.

Wales' hopes for Cardiff had been boosted by England having already lost injured World Cup-winners Jonny Wilkinson, Mike Tindall, Will Greenwood, Stuart Abbott, Richard Hill and Martin Corry.

But the probable absence of 75 times-capped Charvis, especially, is a huge blow to Ruddock as he prepares for his first RBS 6 Nations campaign.

Because of the fact the injury had not made any significant progress, further investigations were carried out by our medical staff, said Ruddock.

These have revealed damage to the ligament which surrounds the bone between the first and second metatarsal.

Because of the injuries we have in the back-row, Richie (Pugh) will officially join up with the squad - and Robin will train with us as an unattached player.

Richie has been outstanding for the Ospreys and Wales Under-21s. He gained national squad experience on last summers tour of Argentina and South Africa.

It has been an eventful - and frustrating - few days for ex-Wales captain Charvis, who was his countrys outstanding player during the recent autumn Test schedule which featured narrow defeats against New Zealand and South Africa.

Charvis return to the Wales camp from a short break in New York was delayed by blizzards which hit Americas east coast on Sunday, and he has now been told the full extent of a worrying injury.

This is obviously a huge disappointment, said the Newcastle star.

But all I can do is continue with the programme of rest and treatment the Wales team doctors have prescribed for me.

The injury has not responded as quickly as I had hoped, and the prognosis is that I could be out for another two to three weeks.

I will just get my head down now and, I hope, see the rest of the guys do well until I can return.

Pugh, who could now be in line for a Test debut, captained Wales at Under-21 level last season and has been a key member of the Ospreys European Cup and Celtic League line-up.