River Plate midfielder Matias Kranevitter has arrived in Spain to complete his move to Atletico Madrid -- but it could be scuppered by his club's desire to keep him until January.
After a summer in which he has been consistently linked with a move to the Estadio Vicente Calderon club, an €8 million deal appears close to completion.
Kranevitter, 22, who has been called in to Argentina's squad for their September friendlies, told reporters he was "very excited to sign for Atletico."
"I've not spoken much with the coach [Diego Simeone], but I know some players already and I'm very happy to be coming to such a big club," he said. "This is the club where I want to play."
But AS reported that although Simeone wants Kranevitter to be available as soon as possible, River Plate insist he must stay until January so he can feature in the FIFA World Club Cup.
River president Rodolfo D'Onofrio said that was not up for negotiation, telling Ole: "Kranevitter leaves at the end of the year -- or he does not leave.
"At no moment have we spoken or signed anything with Atletico for the player to leave now. It is organised for December. Plus, Atletico first have to sign the documents."
Kranevitter said he would leave the matter to the two clubs, adding: "The clubs will need to reach an agreement on whether I stay at Atletico or return to River."
Meanwhile, Mexican billionaire Carlos Slim is reportedly ready to help Atletico finish their new stadium.
El Mundo said Slim, the world's second-richest man, would invest €150-170 million in the project to convert former Olympic venue La Peineta Stadium.