Cardiff Blues have confirmed that Sam Warburton will miss Friday's friendly against Exeter as a result of the civil war blighting Welsh rugby.

Warburton is stuck in limbo by the ongoing dispute between the Welsh Rugby Union and regions and will now miss the opening match of pre-season at Cardiff Arms Park.

The British and Irish Lions captain is the only player centrally contracted to the WRU and cannot be selected until a new participation agreement is reached between the warring parties.

The Blues travel to Leicester on August 29 for their final friendly before RaboDirect PRO 12 action begins against Zebre nine days later.

"Until the services agreement has been sorted we unfortunately can't pick Sam and so he won't be involved against Exeter," Blues attack coach Paul John said. "I've been told by the region that, at the moment, he is unable to play for us.

"Until everything is signed and sealed that will be the case. As soon as it is done we will crack on."

Warburton's inability to play will be particularly galling given that the Wales star is fit and available after recovering from the shoulder injury sustained during the Six Nations in March.

There is little evidence to suggest the WRU and regions will reach an agreement any time soon, so flanker Warburton is facing the real prospect of watching the start of the competitive season from the sidelines.

"Sam is training really well with us and this is probably one of the first pre-seasons he's had in a long while," John said. "He's been a big part of training with us this summer so hopefully things can get sorted and he can start playing.

"Sam was rehabbing with us at the start of the summer and now is back in training.

"I know (Blues defence coach) Dale McIntosh has spoken to (Wales coach) Warren Gatland about him and there is a plan in place in terms of when he can play and things like that.

"From a rugby point of view, we hope to start integrating that plan as soon as possible."