London - Injury concerns are threatening to overshadow Wales coach Warren Gatland's Six Nations squad announcement on Tuesday.
Wales are bidding to win a third outright title in succession, something never achieved before in the tournament's history.
But several senior players may not be fully fit by the time of their tournament opener against Italy in Cardiff on February 1.
Gatland's squad announcement will also take place against a back drop of civil war within Welsh Rugby that has pitted the Welsh Rugby Union against the four professional regions in a battle for the future of the game in the Principality.
The most pressing issue for Gatland concerns Wales captain Sam Warburton -- the skipper of the British and Irish Lions side the New Zealander coached to a 2-1 series win in Australia last year.
Back-row forward Warburton has not played since suffering a shoulder injury during Wales' 30-26 defeat by Australia at the Millennium Stadium in November and Cardiff Blues coach Phil Davies reckons the flanker is still a fortnight away from full fitness.
That doesn't leave Warburton with much time to regain match sharpness ahead of the Italy game.
Prop Gethin Jenkins is also doubtful after he suffered a leg injury in the Blues' European Cup defeat by Toulon last weekend.
Behind the scrum, Jonathan Davies u set to miss the first three games of the Six Nations with the pectoral injury he sustained in Wales's loss to South Africa in November.
But fellow centre Jamie Roberts, who missed the entire end-of-year series, is on course to return from an ankle injury for Racing Metro this weekend.