Wales number eight Taulupe Faletau looks set to miss the Six Nations after breaking his arm again.
Faletau, a British and Irish Lion, suffered a fractured forearm playing for Bath in October and missed the autumn international series.
The 28-year-old returned for his club in Saturday’s 18-16 Champions Cup win over Wasps, and the club confirmed on Tuesday that he has suffered another break.
Faletau is expected to be out for up to eight weeks, with the final round of Six Nations fixtures coming on March 16th.
Wales begin their campaign away to France on February 1st and coach Warren Gatland is due to announce his squad at midday on Tuesday.
Speaking after his side’s game on Saturday, Bath director of rugby Todd Blackadder had been full of praise for Faletau.
“He looked great, didn’t he? Really sharp. If only we could have given him more ball,” Blackadder said.
“I have to give a big pat on the back to our strength and conditioning staff, for the work they do behind the scenes in getting the guys ready.
“Before the game, he (Faletau) was really, really nervous. But it’s good to see those nerves from an experienced guy like him.”
Gatland has several other injury concerns, with Leigh Halfpenny set to miss the start of the tournament as he has not played since suffering concussion during the victory over Australia on November 10th.
Scarlets head coach Wayne Pivac said last week that Halfpenny has seen a specialist and would not feature for "three to five weeks".
Saracens star Liam Williams is likely to fill the fullback spot for the opener in Paris, 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 outhalf 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' curtain-raiser.
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 Pro14 clash against Munster on January 26th.
Ospreys centre Scott Williams and Blues flanker Josh Navidi are 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.