Wales and Lions captain Sam Warburton is being rested for Cardiff Blues' home game against Ulster on Friday.
Director of rugby Mark Hammett confirmed the decision was linked with the open-side flanker's status as a centrally contracted Welsh Rugby Union player.
"We have an agreement with the union over Sam Warburton's availability throughout the season," said Hammett.
Warburton, 25, is currently the only player contracted to the WRU.
He signed a central contract in January 2014 after failing to agree a new deal with the Blues.
But his status meant the Blues did not select Warburton for some pre-season friendlies while the row over funding between the WRU and the four Welsh regions was being resolved.
The signing of the new "rugby services agreement" by the regions and the union on 28 August, cleared Warburton to play, and he has made three appearances for the Blues on consecutive weekends.
"I'm really enjoying my rugby down at the Blues at the moment," he said.
"I've played three weekends in a row and it's all gone well, and it's just great to be playing and not worrying about anything else other than rugby."
The new agreement between the union and regions also cleared the way for more players to be employed on "dual" contracts, jointly funded by the WRU and the regions.
That could lead to more high-profile players having their appearances in Pro 12 matches limited.