Manchester City's Joe Hart (centre) prevents a supporter from reaching Manchester United's Rio Ferdinand (left), who has already been struck in the face by a coin.

Manchester, England – Manchester City apologised to Rio Ferdinand on Sunday night as the Football Association and police launched an investigation into the throwing of a coin which struck the defender above the left eye during a febrile finale to the Manchester derby.

City were examining CCTV footage in an attempt to identify the fan, whose two-pence piece hit Ferdinand as he was about to lift his shirt in triumph after Robin van Persie sealed Manchester United's 3-2 victory and left him wiping blood from his face.

The FA, who will liaise with Greater Manchester Police, said the supporter faces a lifetime ban – as does a man arrested by police on suspicion of fan-on-fan racist abuse after Van Persie's strike. Another supporter, who was prevented by City goalkeeper Joe Hart from approaching Ferdinand after running on the pitch in the late melee, faces a three-year ban. The FA condemned the missile throwing, in which Wayne Rooney was also showered with coins, as “appalling” and “unacceptable”.

Flares were also thrown on to the pitch in a tempestuous conclusion to the game – during which Carlos Tevez made gestures and comments towards his former manager Sir Alex Ferguson and Phil Jones offered shushing gestures at the City fans as he ran to congratulate Van Persie.

Ferdinand, who was also subjected to racist abuse on Twitter, last night tweeted: “Whoever threw that coin, what a shot! Can't believe it was a copper 2p... could have at least been a £1 coin!”

The investigations compounded a desperate afternoon for the City manager, Roberto Mancini, who publicly criticised Mario Balotelli, Samir Nasri and Tevez on Sunday night. Balotelli's City career is in the balance at the very least after Mancini's questionable decision to start with him rather than Tevez backfired.

The striker marched straight past Mancini and down the tunnel after his 52nd-minute substitution and, as he left the stadium last night, his Bentley was surrounded by jeering United fans.

“I love Mario as a guy and a player, but it is important for him to start to think about his job,” Mancini said. “He has everything to play well, we wanted more from him, he has everything but he cannot play like he played today. When you have the quality that Mario has, you can't understand it, how can you throw his quality out of the window?

“I have seen players like that with fantastic quality who end up with nothing, I don't want this for him.”

Van Persie's winner prevented City extending their unbeaten Premier League home record to 37 games and two years – which would have been their longest unbeaten run since 1947. Mancini was critical of the role Nasri played in City's defensive wall – standing behind substitute Edin Dzeko and sticking out only a leg to block the Dutchman's strike. “If you need to put your face there, you need to put your face there. I won two titles with Lazio for this,” he said.

Tevez also left the wall, to pick up Rooney, when the manager had instructed him to remain in the defensive line. “I don't know [why Tevez left the wall]. I understood before that the free-kick was dangerous,” Mancini said. “We made a mistake and only put three players there. We had two and a half players there. I called Carlos to return to the wall, but I was too far away on the bench.”

Mancini's tendency to offer public censure of the players has already annoyed some of them this season and his decision to humiliate Balotelli by removing him only seven minutes into the second half raises new questions about Mancini's man-management skills. “After five minutes, I saw he played like he played in the first half and I didn't want this,” he said.

Of the missile incident, Mancini said: “We have a fantastic support, but we can't do what somebody did. It's not good.” Ferguson added: “The game did not deserve that. The same thing happened at Chelsea [this season] and it was all masked by the [Mark Clattenburg] carry-on.” – The Independent