Warren Gatland has issued a warning to players based outside of Wales, saying that they risk being left out of the 2012 Six Nations tournament.

Gatland wants his players in camp 13 days before their opener against Ireland on Sunday, February 5, but Welsh stars not based in the PRO12 will still be required to play for their clubs.

Mike Phillips, James Hook, Lee Byrne, Craig Mitchell and Andy Powell have already been left out of Wales's clash with Australia in December due to club commitments.

"If those players can't get full release for the Six Nations then they won't be selected," Gatland said.

Wales's regional teams have an agreement with the Welsh Rugby Union that players are available for all the national team's Tests, including almost two weeks of preparation ahead of tournaments, tours and autumn matches.

"I think we need to be a bit careful with one or two that it would depend on, we're not going to put ourselves in a corner if we've got injuries in certain positions," he added.

"I'm disappointed to hear that a couple of them had verbal agreements, but not written in their contracts which I'd sat down with them to do.

"But there is a warning out there if you're going to leave Wales, make sure that you've got it in your contract that you've got full release for all Welsh games and squad sessions. Because if you don't you aren't going to get selected."

Gatland recently announced his 28-man squad to face Australia.