Despite their winning start at home to Scotland last Saturday, the Welsh have suffered a mini injury crisis.
The latest concerns surround outside-half Stephen Jones (back) and centre Sonny Parker (neck).
They both sat out training on Tuesday along with captain Colin Charvis, who is on antibiotics after dislocating his index finger against Scotland.
Jones hopes his back spasm is only a temporary inconvenience while Parker - expected to line up against Brian O'Driscoll on Sunday - underwent a scan on his neck.
"They are just little niggles which we are having checked out and hopefully they will be all right," said Wales assistant coach Scott Johnson. "We are not panicking about the situation."
The other worry continues to be Charvis, who has not trained this week, but Wales are more optimistic about two other forwards, Robin McBryde (back) and Robert Sidoli (groin), who both took a full part in training.
With injuries to fringe players Garan Evans and Hal Luscombe, Wales have drafted in Llanelli Scarlets full-back Barry Davies, the scorer of a memorable European Cup try at Northampton last month to help see his side through to the quarter-finals.
"Barry has performed well at regional level for the Scarlets this season, in fact, as so many have told me, he has been unlucky not to make the team from the start," said Wales coach Steve Hansen.
It is very unlikely Davies will figure in Wales's 22 for the trip to Lansdowne Road.
The starting line-up is likely to see at least two changes if McBryde and Sidoli are passed fit - they would replace Mefin Davies and Gareth Llewellyn respectively - and maybe a third if Charvis pulls out.
In the event of Charvis being ruled out Martyn Williams would be favourite to take over the captaincy.