Sam Warburton will not be available for the Cardiff Blues' friendly against Exeter on Friday, 15 August, because of the ongoing dispute in Welsh rugby.
The Wales captain, 25, is the only player on a central contract with the Welsh Rugby Union (WRU).
He has been training with the Blues, but they say he will not be selected as the regions and the WRU have yet to agree a new participation agreement.
The previous deal covering player release and funding ended in June.
Cardiff Blues backs coach Paul John said the region had no choice over the matter.
"Unfortunately we haven't been able to pick Sam," he said.
"But he's been a big part of training . . . and fingers crossed they will hopefully get it sorted and he can start playing."
Another leading Welsh international, prop Adam Jones, is now training at Welsh Premiership club Neath RFC after starting pre-season training on his own.
Jones's contract with the Ospreys ended in May and he has not been able to agree a new deal because of the impasse.
|What is a central contract?|
|"A player's contract is held by the Union and not by his club, province or region. The Union, who pays his wages, can then determine where, when and even what position he plays. New Zealand, Ireland, Australia, South Africa and Scotland all have their own variations of a central contract."|
The four Welsh regions - Blues, Dragons, Ospreys and Scarlets - represented by Regional Rugby Wales (RRW) are partly funded through the deal with the WRU.
In return, they release players for Wales' national squad training when required, for matches in the International Board Test window and also for international games that fall outside the period set aside for Tests in the IRB calendar.
Central contracts were not covered by the previous agreement and in July RRW warned that they had a legally-binding agreement not to pick any centrally-contracted players.
Warburton opted for a central contract in January 2014 when he was unable to agree a new deal with the Blues.
The 2013 British and Irish Lions captain was one of six Wales international players linked with central contracts in the face of an exodus of talent to clubs in France and England.
Of those, Scott Williams and Rhys Priestland agreed new deals with the Scarlets, Alun Wyn Jones stayed with the Ospreys and Leigh Halfpenny left the Blues for Toulon.
Adam Jones is keen to stay with the Ospreys once a deal can be agreed.