The 24-year-old joined United from Sporting Lisbon for 16 million pounds on Aug. 20 but was ineligible for their games against Sunderland, MK Dons and Burnley while he waited for a British work permit.
Rojo had to leave the United Kingdom to go to the British embassy in Madrid but now the Border Agency has ruled he can have a visa.
The defender had to wait after his Argentina teammate Angel Di Maria, who joined United after him, played at Burnley. Former Real Madrid star Di Maria possesses an Italian passport, which made it easier for him to move to a British club.
Rojo's availability means United could give as many as four of their summer signings debuts against QPR.
Deadline-day recruits Radamel Falcao and Daley Blind ought to be in contention while United are waiting to see if Luke Shaw, who has been sidelined, recovers from his hamstring injury in time to feature.
Finally! I was beginning to think he would never get it due to his legal troubles.