Manchester United's reported interest in signing Marcos Rojo has sparked a feud between his Portuguese club and the third-party fund that claims rights to the Argentina defender.

Sporting Lisbon has taken disciplinary action against Rojo by benching him for the Portuguese league opener over what a club statement calls "interference and illegitimate pressures" to transfer the player by its part-owner, management company Doyen Sports.

Doyen has responded in a statement that Sporting "is in its right not to transfer the player Marcos Rojo knowing that it only has to compensate the fund according to the terms and deadlines contractually established."

Doyen paid 75 percent of Rojo's transfer fee to help Sporting acquire him from Spartak Moscow in 2012.