United signed Rojo from Sporting Lisbon on August 19, but he had to miss the games against Sunderland, MK Dons and Burnley as he was unable to obtain a work permit.
The Argentina international had to travel to Madrid for an interview regarding his permit because of an alleged altercation with a neighbour in his homeland four years ago.
Rojo's paperwork has now been signed off and he is therefore available to feature in United's next game, which is against QPR a week on Sunday.
United tweeted on Thursday: "The UK Border Agency has agreed to grant #mufc defender @MarcosRojo5 a visa and he will therefore be available to face QPR on 14 September."
The 24-year-old played in Argentina's 4-2 win over Germany on Wednesday night
United's record signing Angel di Maria starred in the friendly win, which was a re-run of World Cup final
The £59.7million signing set up three goals and found the net himself in Argentina's victory over the world champions in Dusseldorf
Source : PA
Source: PA