Mike Phillips has been cleared by Bayonne to attend part of Wales' pre-Six Nations training camp in Poland.
Bayonne are to release the scrum-half for the first three days of Wales' ice chambers visit in Spala from 22 January.
Phillips has to be back in France for Bayonne's Top 14 match against Toulon on 25 or 26 January.
Clermont Auvergne have also agreed to let full-back Lee Byrne attend between 23 and 25 January.
But Perpignan have yet to respond to a request to release James Hook.
"There is no problem for the club to allow Mike Phillips to go to the training camp," confirmed Bayonne spokesman Nicolas Bridoux.
"The only thing that we want is that he will play versus Toulon on 27 or 26 January - we don't have the date of the game.
"But he is free to go to Poland for the training camp."
Clermont say they feel obliged to release Byrne as they will French and Italian players for Six Nations preparations.
"The decision is quite straightforward. We will release Lee if he is selected for the training camp in Poland on the 23, 24 and 25 of January," said spokesman Neil McIlroy .
"He should then come back to us on Thursday 26. We do have a league game that weekend [against Bordeaux-Begles].
"To say we are happy. I don't have to go that far. We have a similar obligation with the French players as well and the Italians. That's just life unfortunately. We will just have to work around about that.
"It's not ideal preparation for a Top 14 game that weekend, but we will have to live with that and get on with it."
Coach Warren Gatland has a deal with the four Welsh regions that players report for Wales duty 13 days before tournaments.
But he does not have that luxury with players operating outside Wales, so French clubs do not have to allow overseas players to link up with international teams until five days before a match.
The facility in Spala exposes players to temperatures as low as -120ºC and was used to good effect before the 2011 Rugby World Cup, which saw Wales finish fourth.
The theory is that cooled muscles aid recovery after training sessions and improve rehabilitation after soft tissue injuries.
It is seen as good preparation for their opening Six Nations clash against Ireland in Dublin on Sunday, 5 February.