George North has emerged as a doubt for the Six Nations after being stretchered off during the Scarlets 47-15 defeat by Ulster on Friday.
Flying winger North had to be placed in a brace and backs coach Mark Jones confirmed that he had 'issues' with his head and neck.
Jones said: "I only know what I saw on the replay. He's had a knee to the head and he's struggling with some head and neck issues."
Wales can barely manage another high-profile injury with their list of absentees ahead of the tournament's opening game in early February already a huge concern.
Fly-half Rhys Priestland is out of the competition with a ruptured Achilles and they will have to wrap Jamie Roberts and Leigh Halfpenny, who return from injury later this weekend, in cotton wool to ensure their availability.
The troubles are even worse in the pack where props Craig Mitchell and Aaron Jarvis, hookers Huw Bennett and Ken Owens, locks Alun Wyn Jones, Ian Evans and Luke Charteris as well as flanker Dan Lydiate are sidelined.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.