The 21-year-old Italian committed the studs-up challenge during the opening half of City's 1-0 defeat at Emirates Stadium on Sunday but went unpunished by referee Martin Atkinson.

He was later handed his marching orders after receiving two unrelated yellow cards and is facing a three-match ban for the dismissal.

However, that suspension will not be extended by the FA, which says it cannot take retrospective action because the incident was seen by at least one of the four match officials.

The governing body said a statement: "Retrospective action in relation to the incident involving Mario Balotelli of Manchester City and Alex Song of Arsenal, which occurred in the 20th minute of Sunday's game, will not be taken.

"Where at least one of the officials has seen the coming together of players retrospective action is not taken, regardless of whether they have seen the full extent of the challenge.

No action

"Retrospective action can only be taken in scenarios where none of the Match Officials saw the players coming together. The normal scenarios in which retrospective action is taken are for 'off the ball' incidents.

"Retrospective action was introduced for off the ball incidents where there was no contest for possession and could not be deemed to be re-refereeing an incident.

"In agreement with FIFA, this is how 'not seen' incidents are dealt with retrospectively in England. It is a policy that is agreed with all football stakeholders."

City boss Roberto Mancini has already said he is unlikely to play Balotelli again this season, regardless of whether the FA decides to take retrospective action.