Wales star Josh Navidi is set to miss the bulk of through injury.
The back row man has picked up a hamstring problem which is likely to keep him out of action for around a month.
That means he will be unavailable for the first three rounds of the Championship against Italy, Ireland and France.
He could come back into the equation for the final two matches versus England and Scotland if he recovers in time.
It’s a frustrating blow for the 23-cap Navidi as it’s a repeat of what happened to him at the World Cup.
Out in Japan, he suffered a hamstring injury during the quarter-final victory over France.
That ended the versatile breakaway’s tournament and he was sidelined for two months in all.
He returned for Cardiff Blues in the Boxing Day clash with the Dragons at the Arms Park and has been his usual combative, all-action self in his three outings back for the region.
But now the 29-year-old has been laid low once again.
That leaves Wales down to five fit specialist back rows in Aaron Wainwright, Ross Moriarty, Aaron Shingler, Taulupe Faletau and Justin Tipuric, with Cory Hill providing cover.
Wainwright, Faletau and Tipuric will start against Italy in Saturday’s Six Nations opener at the Principality Stadium, with Moriarty on the bench.
Whether anyone will be brought into the squad as a result of Navidi’s injury remains to be seen.
There’s certainly no shortage of options, with Thomas Young in fine form for Wasps and youngsters Ollie Griffiths, Taine Basham and Shane Lewis-Hughes having all featured in Wayne Pivac’s squad for November’s game against the Barbarians.
Navidi is the second Cardiff Blues player to suffer a hamstring injury while away with Wales preparing for the Championship.
Winger Owen Lane suffered “significant” damage and has had to undergo surgery which means he will be out for some four months.
