Rhys Priestland will have scans today as Wales and the Scarlets sweat on the fly-half's fitness.
The 25-year-old was stretchered off with an Achilles injury after 47 minutes of the Scarlets' home defeat to Exeter Chiefs.
Priestland slipped while taking the ball into contact and could face an extended period on the sidelines.
"Rhys has got an Achilles injury," said Scarlets head coach Simon Easterby.
"We won't know the extent of that until he has a scan. But it didn't look good."
The Scarlets' woes were compounded by further injuries suffered by Aaron Shingler and Samson Lee.
Shingler, a shining light in Wales' autumn campaign, came off with a groin problem while Lee injured his shoulder.
"Aaron Shingler suffered a groin injury and he's been carrying that for a couple of weeks," added Easterby.
"Hopefully he will come through but that didn't look great either."
The injured trio are just the latest worries for Rob Howley ahead of the 2013 RBS Six Nations.
Adam Jones, Aaron Jarvis, Craig Mitchell, Ian Evans, Alun Wyn Jones and Dan Lydiate all remain on the sidelines, as do George North, Leigh Halfpenny and Jamie Roberts.
But Roberts and Halfpenny are both set to be fit for the Championship with return dates pencilled in for mid-January.
"We've had a few opinions now from the specialists and it seems to be about six weeks will be there time where the nerve will have settled down and it'll be safe to go back to play," added the Cardiff Blues full-back
With Liam Williams forced out of the World Cup through injury, lock Luke Charteris and Skills Coach Neil Jenkins say they have to put yesterday's defeat behind them as Wales now look ahead to another physical encounter against South Africa in the quarter-finals of the Rugby World Cup.
Winger Alex Cuthbert is hoping get plenty of ball on the front foot against Australia tomorrow at Twickenham as Wales seek to halt the Wallabies' 10-match winnning streak which stretches back almost seven years.
Twelve young people have been selected to follow a one year WRU Coach Core apprenticeship programme. Coach Core was set up by the Royal Foundation of the Duke and Duchess of Cambridge and Prince Harry as part of the Olympics legacy in 2012 and the Duke of Cambridge was on hand to meet the apprentices on their first day in the job. The programme has been funded by the Hunter Foundation.
We look back on the victory over Fiji that makes it three from three for Wales in this World Cup, in a special extra Principality Welsh Rugby Union Podcast. We hear from Wales coach Warren Gatland, captain Sam Warburton, plus Gethin Jenkins, Tomas Francis, Alun Wyn Jones, Dan Biggar, Matthew Morgan and Tyler Morgan, as well as defence coach Shaun Edwards and getting the Fijian perspective from coach John McKee.
We look forward to the Ospreys v Blues derby clash in this week's Principality Welsh Rugby Union Podcast. Ospreys No 8 Dan Baker talks about the pain of missing out on the World Cup, as does Dragons wing Tom Prydie. Blues director of rugby Danny Wilson looks forward to his first Welsh derby in charge, we also hear from Dragons lock Matthew Screech and Wales Sevens team manager Steff Thomas.