News emerged on Saturday that the 76-year-old had been rushed to hospital for an operation, with United later confirming that the procedure had "gone very well".
However, Ferguson is expected to be in intensive care for the foreseeable future, and no further update is expected on his situation in the short term as he continues to recover.
"The surgery going well means the surgeons have achieved what they set out to achieve," Chris Chandler, a consultant neurosurgeon at King's College, London, told Sky Sports News.
"If he had a blood clot, it means that blood clot has been removed successfully and the patient is now in intensive care.
"We don't know exactly what kind of brain haemorrhage he had. There are many different kinds, all of which have vastly different outcomes for the patient. We have to now wait for more information before anybody can say what the outcome is likely to be."
Ferguson is widely regarded as one of the greatest managers in football history, having led United to 38 trophies - including 13 Premier League titles - during his 26 years at the helm.