Manchester United defender Marcos Rojo has been ruled out of Argentina's forthcoming fixtures due to an ongoing injury problem.

The 25-year-old has not featured for his club side since damaging his hamstring in the 3-2 win over Southampton last month.

Rojo has now been officially deemed unfit to take part in Argentina's World Cup qualifying double-header, joining Lionel Messi, Ever Banega and Enzo Perez on a growing casualty list.

"Marcos Rojo will not be part of the squad for the qualifying debut against Ecuador and Paraguay, as he is in the final phase of recovery from a grade 1 injury in his right hamstring," the Argentine Football Association confirmed in a statement.

"Louis Van Gaal, the Manchester United coach, was in touch yesterday afternoon with Argentina coach Gerardo Martino to explain to him the convenience of the defender finishing his recovery in the club.

"The situation was understood by the Albiceleste trainer, who will hope to have Rojo in top condition for the second qualifying double-header against Brazil and Colombia, in November."

Rojo has featured just twice for United this season in all competitions, amid suggestions that he is a January target for Zenit St Petersburg.