Marcos Rojo will become a Manchester United player and sign a five-year contract, subject to a medical, after the Argentina defender's complicated third-party contractual position was finally untangled last night.

Sporting Lisbon confirmed via their official Twitter account that the 24-year-old will move to Old Trafford, with the Portugal winger Nani moving back to his former club on a season-long loan: "#mufc has reached agreement with Sporting Lisbon to sign defender Marcos Rojo, subject to a medical and personal terms. A further announcement will be made when the process is complete."

Rojo's expected arrival means United have finally signed another player after Luke Shaw and Ander Herrera were bought in June for a combined €68 million. His signing for around €20 million takes the club's spend in the current window to €88 million.

United faced particularly complicated negotiations due to Rojo having more than one third-party entity with part ownership that had to be satisfied before the deal could be completed.

With club sources characterising the deal as among the most intricate of United’s recent transfers – the Doyen Sports Investment player fund are understood to have had a significant financial interest in Rojo – there is relief at Old Trafford he will become the first player bought who was identified solely by Louis van Gaal since he became manager in the close season.

Although the Dutchman signed off the deals for Shaw and Herrera, both players had been picked by his predecessor, David Moyes.

Rojo described the 20-times champions as his "dream" club. Although Rojo's arrival is viewed as a formality, this contrasts with any potential move for Real Madrid's Ángel di María. Sources at United stress that neither Van Gaal or any other executive has had any contact or discussions with the player about taking him to Old Trafford.

The situation could change as the September 1st transfer deadline is less than two weeks away.

Paris Saint-Germain, the French champions, remain hopeful of landing Di María, this time on a loan deal after a permanent move fell through due to the fee demanded by Real Madrid.

Rojo played left-back in Argentina’s run to the 2014 World Cup final, which the nation lost to Germany. Guardian Service