Hume was readmitted to hospital on Monday evening, just over two weeks after the incident during the local derby at Oakwell on November 8.

The 25-year-old spent the night at Salford Royal as a precaution after complaining of feeling unwell at home in Oldham, but is expected to return home tomorrow.

Morgan was booked for the challenge during the match, but referee Andy D'Urso's decision not to send him off infuriated Barnsley officials, who forwarded video footage of the incident to the FA.

But the FA confirmed today they will be taking no further action against Barnsley-born Morgan, a former fans' favourite at Oakwell who joined the Blades in 2003.

A statement from Barnsley read: "Barnsley FC is extremely disappointed and concerned that the FA has failed to take any action regarding the violent conduct of Chris Morgan, which left Iain Hume requiring emergency hospital treatment for a fractured skull and bleeding to the brain.

"The decision by the FA to disconnect a violent act from its consequences runs contrary to the principles of civil and criminal law."

Barnsley's anger has been compounded by the FA's decision to charge manager Simon Davey with improper conduct for comments made to a match official.

Davey, sent to the stands for verbally abusing a linesman for his part in a late penalty decision, has until November 28 to respond to the charge.

The club's statement added: "It reflects badly on football that the only action which the FA has thought fit to take was to charge Barnsley FC's manager with misconduct in relation to alleged verbal abuse towards a match official, while violent conduct has gone unpunished.

"The FA's failure to act has let Iain Hume down badly and the only option now remaining is for recourse outside of the normal football processes."

The FA's earlier statement read: "When judging whether to take disciplinary action in this case, the FA has had to consider the challenge itself and not the outcome of it.

"The FA has been given express direction from FIFA that we cannot upgrade yellow cards to red.

"On this basis, we can only bring additional charges in the most exceptional cases and only if it can be proved beyond doubt that the actions of a player were a deliberate attempt to injure an opponent.

"Having reviewed all available evidence in this case, including submissions made by Barnsley, there is no basis on which an additional charge could brought."