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
WRU group chief executive Roger Lewis explains the new Rugby Services Agreement with the Regions in this week's Principality Welsh Rugby Union Podcast. We also hear from Wales forwards coach Robin McBryde as the Vale Resort is confirmed as one of the World Cup bases, welcomed by Vale sales and marketing director Paul Beddoe. We also cover the Fosters National Sevens with reaction from Llanelli's plate winning captain Duane Eager, while Llandovery lifted the main prize and we speak to coach Lyndon Lewis and captain Matthew Jacobs.
The Women's Rugby World Cup warm-up clash between Wales and USA proved bittersweet for centre Elen Evans. Despite being one of the star performers on the day on her 50th Test appearance, USA edged home 10-7 at Cross Keys.
Wales U20 head coach Byron Hayward and back row Will Boyde believe defence will be the key when they face Ireland tomorrow in the second pool game of the Junior World Championship being held in New Zealand.
Tension was palpable as players waited to hear the announcment of the Wales touring squad of South Africa. Matthew Morgan was one of four uncapped players named in the squad after impressing in the Wales Senior Trial.
Wales Trial, Principality Premiership Awards evening and Wales U20s in this week's Principality Welsh Rugby Union Podcast. We hear from Jamie Roberts and Matthew Rees about the Wales Trial, captain Dafydd Lockyer talks about Pontypridd dominating the Principality Premiership awards, while ahead of the start of the Junior World Championships we talk to Tom Williams, Steffan Hughes, Jack Dixon and Nicky Smith.
Coaches Rob Howley and Robin McBryde today confirmed their Probables and Possibles teams to take part in Friday's Wales Senior Trial at the Liberty Stadium and both are predicting some mouth-watering head-to-heads.
Possibles coach Robin McBryde has given his team a licence to thrill in Friday's Wales Senior Trial match. He tells WRU TV's Graeme Gillespie that his side will be determined to ruffle a few feathers against the favourites, the Probables.
We look at the squads for the Wales trial, European finals weekend and Wales U20 on this week's Principality Welsh Rugby Union Podcast. We hear from Warren Gatland and Rob Howley on the trial, full back Hallam Amos on his summer hopes, Wales legend Ieuan Evans welcomes European rugby finals weekend to Cardiff and Wales U20 hooker Ethan Lewis looks ahead to the Junior World Championships.
Wales Under 20 head coach Byron Hayward says last night's 31-19 win over Scotland was a crucial building block as the Junior World Cup rapidly approaches. WRU TV's Liz Jones gets his post match reaction.
Scarlets skipper Ken Owens said his players have "taken it on the chin" from the coaches in the wake of last weekend's six-try defeat in Dublin and are ready to made amends against Benetton Treviso on Saturday night.