Wales are still harbouring hopes that Jamie Roberts will be fit to face Samoa at the Millennium Stadium on Friday evening.
Roberts' absence was keenly felt in Wales' shambolic second-half capitulation to Argentina at the weekend and defence coach Shaun Edwards has underlined the importance of having him back in the side on Friday.
Roberts is suffering from mild concussion after being forced off in the first half against the Pumas while his regular centre partner, Jonathan Davies, is battling to overcome a groin problem.
"For me, Jamie Roberts is vital because he is the defensive captain. Everyone is hoping he will be right for Friday night," said Edwards.
"I definitely want him to play because he is one of our premier defensive players, and there is no doubt we missed him on Saturday
"But you have got to be guided by the medics, and that is what we will do. If he is not, then someone has got to step up in his place and try to fill his boots, which are quite large boots to fill.
"But I am a big believer that rugby is a team game. If your forwards don't perform, your backs can't perform. I try not to make too much of individuals, more the team unit."