Juan Imhoff (AP)
Bagshot - Argentina will go ahead with a threat to exclude Juan Imhoff and other Europe-based stars behind their World Cup success unless they join a new Buenos Aires Super Rugby side, a top official said.
Puma legend Agustin Pichot warned ahead of Sunday's World Cup semi-final against Australia that the measure was necessary to stop wealthy European clubs taking Argentina's top talent.
A Buenos Aires franchise will join the Super Rugby Southern Hemisphere club tournament in 2016.
But Imhoff, scorer of five tries at the World Cup, has pledged his future to Racing 92 in France until 2018.
Prop Marcos Ayerza and tough-tackling centre Marcelo Bosch have also promised to stay with English sides Leicester and Saracens.
They had all hoped for Puma exemptions. But Pichot said there is no chance.
"We have talked with Juan. He understands the reasons why if he does not play for the franchise he will not be selected," Pichot, Argentina's representative on World Rugby, told AFP.
"It is a policy like they have in New Zealand. We adopted it because it has had good results for them."
Defending World Cup champions New Zealand and countries like England also do not let foreign-based stars into the national team. Australia has eased its restrictions however.
Pichot captained Argentina and played for Racing in France and Bristol in England. But he said Argentina could not afford to lose its best players.
"We do it for protection, otherwise the European market will dominate all our players," he said.
"That does not mean that Juan cannot play for the Pumas in the future -- if he plays in the franchise," Pichot added.
"We offered Juan a contract, the Argentinian union offered Juan a contract, but he did not accept. The door is still open because Juan is a great player."
Pichot said there would be no exceptions.
"It is not planned. We will do the best for the franchise."
Before the World Cup, Imhoff -- who carried out a spectacular swan dive try against Ireland in the quarter-final -- said his mind was made up.
"I feel good at Racing. I have been lucky and today I am living a dream. I take responsibility for this decision," he told AFP.
Ayerza, one of the world's top loosehead props, said this week he does not want to give up the Pumas and still hopes there would be exemptions.
"I had committed to Leicester before Argentina made any confirmation of the new policies," said Ayerza. "I don't know if there will be any exceptions.
"I play every game wearing this jersey as if it is my last. You never know with injuries and coaches' likes and dislikes or policies."
Pichot said competing in the Southern Hemisphere's Rugby Championship against Australia, New Zealand and South Africa has been crucial in Argentina's improvement in the past two years.
The Buenos Aires team will join Super Rugby along with a new Japanese team from early 2016.
"Competition is the most important thing," said Pichot. "You can train all you want, but if there is no league it means nothing.
"Super Rugby is the NBA of rugby and Argentina will be playing. This can only improve the Pumas and help them keep improving."
Pichot said Argentina was capable of hosting a World Cup but there was no plan in the medium term to make a bid.