A row has broken out between the representatives and part-owners of reported Manchester United target Marcos Rojo and his current club Sporting Lisbon.
Argentina defender Rojo is currently the subject of disciplinary action by the Portuguese club after apparently refusing to train amid reports of a £16million bid from United.
Management company Doyen Sports, which owns 75% of the player, has now hit back over Sporting's stance and threatened legal action if fees due to it from any rejected bid are not paid.
It is reported that Doyen is entitled to a payment from Sporting worth 75% of any declined offer for Rojo. In this instance that would equate to £12million.
In a lengthy statement, Doyen Sports has stressed it cannot interfere in transfer business and that Sporting have a right to retain the player.
But it has pointed out that in such a scenario the club still have obligations to the company.
The statement read: "Sporting is entirely within its rights not to transfer the player Marcos Rojo, knowing that it only has to make up for the fund under the terms and deadlines as contractually established since the beginning."
It added the company "will not hesitate to use all legal resources at our disposal to defend fully all our interests and rights".
Doyen holds strong rights over the player after paying 75 per cent of his transfer fee from Spartak Moscow in 2012.
The statement added: "Without the intervention of Doyen, through financing, Marcos Rojo would not be a Sporting player."
Sporting, who are reported to be holding out for a figure closer to the player's £24million release clause, have also confirmed that Spartak are owed 20% of any fee received for Rojo above #4million.
Meanwhile, United were handed an away tie at MK Dons in last night’s draw for the Capital One Cup second round.
It is the first time United have had play in second round of the competition in 19 years after their failure to qualify for either the Champions or Europa League last season, as sides involved in European competition are exempt until the third round.