Marcos Rojo
Rojo's future hangs in the balance as Sporting and Doyen head towards legal clash.Getty

Manchester United's pursuit of Marcos Rojo has taken another twist after Doyen Sports, the group that holds a 75% stake in the player's contract, criticised Sporting Lisbon's attempts to hold onto the player by any means necessary.

United are understood to have made a €20m (£16m) offer to bring the Argentine international to Old Trafford. According to reports, the player subsequently handed in a transfer request and was absent from training in an attempt to speed up a move away from the Portuguese club.

Sporting's president Bruno de Carvalho responded by warning Rojo he will face "strong disciplinary measures" for his actions and will miss the club's season opener against Academia.

These recent developments are of a concern to Doyen. The group helped the underfunded Portuguese club sign the 24-year-old from Spartak Moscow in 2012 by financing three quarters of his transfer fee. While they insist Sporting have no obligation to sell the player, the structure of the deal hands Doyen significant influence in any proposed transfer.

With Rojo's future under the spotlight, the group have claimed in a statement that the Portuguese club must compensate them if they refuse to do business with United, in accordance with a contractual agreement.

One World Sports claim that compensation fee will be the equivalent of 75% of any transfer fee Sporting reject from United, meaning the club may have to pay €15m to keep the player if an offer of €20m has been tabled.

In a lengthy statement, Doyen claim Sporting informed them of their plans to cash in on Rojo this summer, a scenario the group believe would have benefited all parties involved.

Doyen maintain their long-standing policy of not forcing clubs into selling their players, but they have warned Sporting a possible legal battle could erupt if contractual obligations are not met.

The statement read: "Obviously, the company has to protect its interests; if there are no rules contracted between the parties, the investment could may never generate any return and possibly even lose any invested funds.

"Sporting is therefore in its entire right not to transfer the player Marcos Rojo knowing that it only has to compensate the fund under the terms and deadlines as it is contractually set forth."

It also adds: "If necessary, make it clear that we will not hesitate to use all legal resources at our disposal to defend fully all interests and rights."

United manager Louis van Gaal is under pressure to strengthen his United squad in the coming weeks. The Dutchman will be without £27m signing Luke Shaw for the first month of the season with a hamstring injury, with Jonny Evans and Antonio Valencia likely to miss their season opener against Swansea City.