Scarlets prop Rhodri Jones is a doubt for Wales' Six Nations campaign after dislocating his shoulder in Saturday's 22-10 Pro12 derby win over Ospreys.
The 22-year-old tight-head featured in the squads for all four of Wales' November Tests and signed a new dual-contract last week.
Jones was injured in the 60th minute having come off the bench at half-time.
"Rhodri Jones has dislocated a shoulder unfortunately, so we'll just have to see," Scarlets coach Wayne Pivac said.
"They put it back in but he is in a lot of pain obviously."
Scarlets hooker Emyr Phillips is also a doubt for Wales in the Six Nations as he needs surgery on a dislocated shoulder, while fellow Scarlets hooker Ken Owens is yet to return after undergoing neck surgery in September.
Wales begin their Six Nations campaign at home to England on Friday, 6 February, before ending the tournament away to Italy on Saturday, 21 March.
Scarlets suffered a further blow to their front row as hooker Kirby Myhill also left the action against Ospreys with a suspected torn pectoral muscle.
The injuries took the gloss off a fine win over Ospreys, ending a run of defeats against their west Wales rivals that stretched back to 2011.