On the positive front Patrice Evra is fit again, while both Chicharito and Antonio Valencia are "doing well" in training and Darren Fletcher came through his outing for the Reserves this week unscathed.
Rio Ferdinand is also on the mend from the hamstring strain picked up at West Brom last weekend. The England defender was expected to be out for around six weeks, but Sir Alex has revealed he could be back to face Arsenal at the end of this month.
Unfortunately though he will not be linking up with his regular defensive partner Nemanja Vidic for a while with the skipper likely to be out action for another month or so.
"Last week we thought Rio's hamstring would have him out for six weeks and with Vidic, we thought it was just a nerve problem. That's reversed itself," Sir Alex told reporters on Friday.
"Vidic has got a calf muscle injury, which means he'll be four to five weeks. It's longer than we thought. Meanwhile, Rio's injury isn't as bad as we thought and he could be ready for our game against Arsenal. I don't think he'll be ready for Monday. It's amazing how circumstances can change in a few days.
"Rafael has had an operation [on his shoulder] this week and will be out for 10 weeks," added the boss. "It was a freak injury really. He won a tackle [in training], stumbled and fell on his shoulder.
"Patrice is back which gives us experience. Chicharito is back training and doing very well as is Valencia who will play in the Reserves next week. When will we bring Chicharito back? It depends. From a medical point of view, considering he had a concussion before, we have to decide when is the best