Jerome Boateng has undergone an operation on the knee he injured in training on international duty with Germany.
The 22-year-old defender is due back at Carrington next week, when an assessment will be made as to when he can begin his rehabilitation work.
Meanwhile, hamstring tear victim Micah Richards is sleeping in an oxygen tent in his desperate bid to beat the clock and beĀ fit for the FA Cup semi-final derby at Wembley on 16 April.
Pablo Zabaleta has also returned to training at Carrington after flying back from Argentina, where his father is now recovering from serious injury following a car crash.
