Wales coach Warren Gatland has several injury concerns as he prepares to name his Guinness Six Nations squad on Tuesday.
Leigh Halfpenny looks set to miss the start of the tournament as he has not played since suffering concussion during the victory over Australia on November 10.
Scarlets head coach Wayne Pivac said last week that Halfpenny has seen a specialist and would not feature for "three to five weeks".
— Welsh Rugby Union 🏉 (@WelshRugbyUnion) January 14, 2019
Saracens star Liam Williams is likely to fill the full-back spot for the Six Nations opener against France in Paris on February 1, with Italy providing Wales' second opposition in Rome eight days later.
Dan Biggar is also nursing a knee injury suffered in Northampton's European Challenge Cup defeat to Clermont Auvergne.
The outside-half limped off with what Saints director of rugby Chris Boyd described as a "minor knee twist", although Biggar is expected to be fit for Wales' Six Nations opener.
Ospreys lock Adam Beard suffered a neck injury over the festive period but should be fit to resume his second-row partnership with skipper Alun Wyn Jones.
Gatland must make further checks on Rhodri Jones (shoulder), James Davies (knee), Nicky Smith (ankle), Dan Lydiate (elbow), Rhys Patchell (hamstring), Jake Ball (shoulder) and Bradley Davies (knee).
Dragons back-rower Ross Moriarty has also been sidelined since suffering concussion last month, but has been pencilled in to return in the Guinness PRO14 clash against Munster on January 26.
Number eight Taulupe Faletau will return after breaking his arm in October.
Faletau missed Wales' unbeaten autumn international series, but he impressed in his comeback game for Bath last weekend.
The 28-year-old set up the opening try in their Heineken Champions Cup win against Wasps with a powerful run, and Bath boss Todd Blackadder said the British and Irish Lion "looked really sharp".
Ospreys centre Scott Williams and Blues flanker Josh Navidi are also expected to return after missing the autumn with respective hamstring and knee injuries.
But Scarlets flanker Aaron Shingler (knee) remains out and Blues captain Ellis Jenkins is another absentee as he continues his recovery from ACL surgery.