Leigh Halfpenny: Scarlets full-back ruled out of Champions Cup match
|European Champions Cup: Scarlets v Ulster|
|Venue: Parc y Scarlets, Llanelli Date: Fri, 7 Dec Kick-off: 19:45 GMT|
|Coverage: Listen live to BBC Radio Wales and BBC Radio Cymru commentary on the BBC Sport app and website, plus live score updates|
Leigh Halfpenny will miss Scarlets' European Champions Cup match against Ulster on Friday because he has not recovered from concussion.
The full-back was injured during Wales' 9-6 win over Australia on 10 November.
Lock Jake Ball has passed Head Injury Assessment (HIA) tests after being forced off against Glasgow on Saturday.
Prop Samson Lee (hamstring) and flanker James Davies (knee) could return but back-row forward Blade Thomson is being given an extended break.
The Scotland-qualified New Zealander has not played since receiving a blow to the head against Edinburgh on 2 November - an injury which prevented him challenging for an international debut in the autumn Tests.
"Leigh's been ruled out, we're giving that a bit more time, just being on the safe side really with the back three we've got," said head coach Wayne Pivac.
"We've got a strong group there, so we don't want to push things and we've got to tick all the boxes at the right time."
Halfpenny's extended lay-off means he has missed two Wales Tests - against Tonga and South Africa - and Scarlets' 26-20 defeat by Glasgow on 1 December.
He will have been out of action for more than a month by the time he returns.
The British and Irish Lion was injured in the dying minutes of Wales' 9-6 win against Australia in a challenge by Wallaby centre Samu Kerevi described as "reckless" by Wales coach Warren Gatland.
Scarlets will be boosted by the return of Hadleigh Parkes, Gareth Davies and Ken Owens after international duty, and Pivac remains hopeful Ball will also be available.
"Jake's hitting all his markers from an HIA point of view, so hopefully he keeps ticking those boxes, and there's a slot to fit him into," added Pivac.
"James (Davies) has been in contact (sessions), if he comes through (training) he'll be available for Friday but it's a big 'if' because the work-load is very intense and he's been out for 11 weeks."