Marouane Fellaini's problematic first season as a Manchester United player has taken another turn for the worse after it emerged he is being investigated by the Football Association for a possible spitting offence against the Manchester City defender Pablo Zabaleta.

The FA are reviewing footage from City's 3-0 defeat at Old Trafford to establish whether Fellaini spat at Zabaleta in the aftermath of elbowing his opponent to the ground. Zabaleta was lying on the floor when the follow-up incident allegedly took place and the FA have seen footage, shot from behind Fellaini, that appears to incriminate the former Everton midfielder.

Zabaleta has also seen the television pictures and, though City will not lodge an official complaint, the club are expecting the FA to look further into it. The Argentinian had his hands covering his face at the time and did not see, or feel, anything other than the blow to the side of his head from Fellaini's elbow.

If the FA think there is sufficient evidence, Fellaini will be charged with misconduct and the offence will carry a three-match ban, in line with George Boyd's punishment for his clash with Joe Hart when Manuel Pellegrini's team played at Hull City on 15 March.

The governing body will first request that Sky pass over the various camera angles from the relevant passage of the game. United will also be asked to submit their own footage. As it stands, Fellaini's face cannot be seen and the FA are likely to need something more conclusive. Nothing was reported on the night and the referee, Michael Oliver, clearly did not see anything.