Marcos Rojo
Manchester United manager Louis van Gaal is likely to step up their search for a left-back in January after Marcos Rojo (R) suffered an injury during trainingGetty

Manchester United have suffered yet another injury blow after defender Marcos Rojo dislocated his shoulder during training on Wednesday (2 December). It is the same shoulder that kept the Argentine on the sidelines for a month last season after he injured it during the Manchester derby.

According to the Mirror, the defender was taken for scans immediately and the club medical staff fear that the former Sporting Lisbon defender could be out for weeks and have not ruled out the possibility of surgery. The extent of the damage is still unclear, with Louis van Gaal set to give an update during his pre-match media briefing on Friday ahead of their clash against West Ham United on Saturday (5 December).

This will come as a huge blow for the Dutchman, who is facing an injury crisis in the full-back positions, with long-term absentees Luke Shaw and Antonio Valencia unlikely to return at least until March. The former suffered a double leg break earlier in the season, and the Argentine has deputised for him at left-back. The injury to Rojo could see Daley Blind shifted to the left with Paddy McNair or Phil Jones, who is also currently injured, coming in to partner Chris Smalling at center-back.

Rojo angered the manager after missing United's pre-season tour of the United States, and spent the first few weeks of the Premier League season trying to get fit. He fell out with Van Gaal again following his return to the first-team after failing to report a hamstring injury to the medical staff during the game against Southampton. The Dutchman, however, reinstated him and has even praised him in recent weeks for his performances in the Champions League.

The 25-year-old defender's injury is likely to force the former Bayern Munich manager to step up his search for a left-back, after admitting earlier in the season that they could sign cover for Shaw. According to Manchester Evening News, the club have sent scouts to monitor Porto left-back Bruno Martins Indi.