Wales flanker Aaron Shingler is to undergo further treatment on an ankle injury.
The Welsh Rugby Union announced that 26-year-old Shingler has been released from the Six Nations squad back to his regional team the Scarlets.
Shingler picked up the injury in training last week. He has won seven caps, but he was not part of the match-day 23 when Wales opened their Six Nations campaign with victory over Italy two days ago.
Dan Lydiate, meanwhile, expects another fierce battle when Wales and Ireland renew their intense rivalry next Saturday.
Wales will head to Dublin after winning three of the last four meetings, including a 2011 World Cup quarter-final triumph in New Zealand.
“The last few games against Ireland have been real battles, and I expect it to be the same this time,” Wales flanker Lydiate said. “The match will probably hinge on a couple of incidents that could swing either way, and it could be a good spectacle.
"After the Lions tour there are a lot of Irish boys you are friendly with. I am playing at Racing Metro now with Johnny Sexton, so I am really looking forward to coming up against him.
“I am sure there will be a few texts in the week and some banter.”
With Wales captain Sam Warburton successfully beginning his comeback from injury through a second-half appearance off the bench during a 23-15 victory against Italy on Saturday, head coach Warren Gatland looks set to recall him.
Given Warburton's effectiveness at openside and blindside flanker, it would mean either Lydiate or Justin Tipuric dropping out if Gatland fields his skipper in the starting XV.
“Sam has been out a while. It’s good to see him back on the field,” Lydiate added. “It would have done him the world of good to get the 15 or 20 minutes, and we will see what happens next week.
“We have got two world-class sevens now, and ‘Tips’ has been on fire all season. I have played with both of them, and they have played together as well, which they did so well last season.
“The coaches are spoilt for choice at the moment, and Ireland are the same. They are missing (Sean) O’Brien, but they have so much depth in the back row.”
