Wales are likely to be without George North and Justin Tipuric for their opening Six Nations game against Ireland.
The Ospreys duo are rated as unlikely to recover from injury in time for the 5 February match at the Aviva Stadium.
Flanker Tipuric, who won 14 of his 86 caps against Ireland, injured his shoulder during the Lions tour of South Africa, while wing North damaged his knee while playing for his club against Cardiff.
Asked if Tipuric would be fit for the Dublin clash, Ospreys head coach Toby Booth, quoted on Wales Online, replied: "I don't think so.
"From what I can see, no, I don’t think he will be. He is not in training. It’s just slow.
"Part of the scenarios are around range and motion, pain management and response to treatment.
"We are governed by how his body reacts."
On North, who has scored 45 international tries in 105 games, Booth said: "Currently I would be erring on the side of 'no’.
"I’ve seen George around the place doing a lot of training with the injured group.
"The first step for him is that he’s allowed to start doing warm-ups, for example, in main rugby sessions. That is great for players psychologically because they know they are getting close.
"But I saw him earlier today and he seemed in quite a good mood.
"We’ll have our usual medical update, but he’s certainly making progress.
"But for a person like George and the position he plays, lower body power is massive, so we have to make sure we tread very carefully."
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