All Blacks great Richie McCaw and the Irish first five Jonny Sexton have urged rugby leaders to move the June internationals and adopt an integrated global season to improve player welfare and safeguard the future of the game.
The pair have thrown their weight behind a proposal by the International Rugby Players' Association to make the changes for the 2016 season that would help all test playing nations to pick their best players.
The IRPA want to move the June test window back to the end of July, allowing the Southern Hemisphere-based players to finish the Super Rugby club season, while those in Europe would start their domestic campaigns later, possibly October.
McCaw says if the game's give the concept serious consideration it could be a game-changer for professional rugby.
The Players Association has asked the International Rugby Board, SANZAR, European clubs and the Six Nations to discuss the issue before agreeing to terms for the years ahead.