Scott Williams has been released from the Guinness Six Nations
squad and will return to Ospreys for treatment on a back injury.
The Welsh Rugby Union confirmed the problem was expected to sideline Williams for the rest of the campaign, which continues against England at the Millennium Stadium on February 23.
Williams' departure follows on from the news number eight Taulupe Faletau had undergone surgery to his broken right arm which also ruled him out of the remainder of the Six Nations.
Warren Gatland's squad are currently second in the table following two wins from their opening two matches, securing victory in Paris with a superb second-half fightback before seeing off Italy 26-15 on Saturday.
After the players reconvened at the WRU National Centre of Excellence on Wednesday, a decision was taken on Williams' fitness.
A statement on the WRU website read: 'Scott Williams has been released from the 2019 Guinness Six Nations squad to continue rehabilitation of his back injury at his Region.
'It is felt that his injury will preclude him from taking a competitive part in the competition.
'An update will be provided later today regarding players released back to their Regions for action this weekend.'
Wales assistant coach Shaun Edwards confirmed full-back Leigh Halfpenny, who has been out following a concussion, fly-half Rhys Patchell and prop Leon Brown were all able to join in for a large part of training on Wednesday.
Edwards maintains the players will be ready to push themselves again when they go head-to-head with England in Cardiff.
'We don't want to get pumped up too soon,' Edwards said to WRU TV.
'We probably did not do a good job on that this morning because there was certainly a little bit of fire and brimstone in the training session.
'It was a very, very tough session and the boss was in great form.'
Edwards added: 'We feel that we can play better than we have done in the past two games.
'We don't feel probably we have achieved the level of performance we had in the autumn, but hopefully our best is yet to come in this Six Nations.
'The fact that they are winning and being quite critical of themselves as well, they want to improve.
'We want to get better and we know we will have to do that to beat England.'