Villa later released a statement saying Olsen is "completely fine", confirming he did take a bang on the back of the head, but indicating nobody was sure if the incident was deliberate or an accident. Villa said they consider the matter closed and will not be making a complaint.

Thousands of Man City fans ran onto the pitch at the Etihad Stadium at full-time as Pep Guardiola's side were crowned Premier League champions in dramatic circumstances.

Asked if players got off the pitch safely, Villa boss Steven Gerrard said: "No is the answer to that. My goalkeeper was attacked. So I think those questions should go to Pep and Manchester City."

Asked about Olsen's condition, Gerrard added: "We're going to check on him."

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City manager Pep Guardiola admitted the incident had been the low point of the day.

Guardiola said: "I'm so sorry on behalf of the club to Olsen and Aston Villa.

"I don't think there were intentions, but the emotions of people there, it's always difficult to understand why people respond in that way and cannot celebrate themselves and not do these kind of things. Hopefully, we can discover who the person was and he'll be punished.

"I don't know how (to stop it). You cannot put 1,000 guards to control all the people there. We are so sorry. It's the bad news of today."

The club earlier released a statement reading: "Manchester City would like to sincerely apologise to Aston Villa goalkeeper Robin Olsen, who was assaulted after the final whistle at today's match when fans entered the pitch.

"The club has launched an immediate investigation and once identified, the individual responsible will be issued with an indefinite stadium ban."

Greater Manchester Police said: "Officers are working alongside Manchester City and Aston Villa Football Clubs following a reported assault that took place on the pitch after Manchester City's fixture against Aston Villa on Sunday 22 May 2022. A footballer was reported to have been assaulted following a pitch invasion at the end of the game, with no injuries reported. Officers are working in partnership with both football clubs to identify those responsible."

The Football Association also said that they would be investigating the pitch invasion.

Supporters have run onto the field after a number of recent high-profile Premier League and EFL matches, with a Nottingham Forest fan jailed for 24 weeks after headbutting Sheffield United's Billy Sharp.

Crystal Palace manager Patrick Vieira was involved in an altercation after Everton fans invaded the pitch on Thursday and fans streamed onto the field on Sunday after City's 3-2 comeback win against Aston Villa which secured the Premier League title.

City retained their Premier League in extraordinary circumstances after coming from two goals down to beat Aston Villa 3-2 at the Etihad Stadium.

Three goals in five minutes late in the game turned the match - and the title race - on its head as substitute Ilkay Gundogan scored two, either side of Rodri's strike. Liverpool's late win over Wolves meant that only victory would have been enough for City.