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.
Thousands were on the Etihad Stadium turf after wrapping up the Premier League title and Villa boss Gerrard says goalkeeper Olsen was hurt.
Asked if everyone got off the pitch OK, Gerrard said: “The answer is no. My goalkeeper was attacked. I think those questions should go to Pep and Manchester City.”
City swiftly released a statement apologising to Olsen.
“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 said.
“The club has launched an immediate investigation and once identified, the individual responsible will be issued with an indefinite stadium ban.”
The incident sparked an angry reaction from former Ireland captain Roy Keane, who suggested the recent surge in pitch invasions in English football could end with a tragedy.
"Disgraceful, it really is. I tell you, a player or a manager is going to be seriously injured," Keane told Sky Sports.
"If you're mad enough to come on and punch a player then you're silly enough to stab them or something. Something crazy will happen. I think people have come back from Covid and forgotten how to behave themselves.
"Idiots. Scumbags. Disgrace. A player walking off the pitch and getting attacked, we've seen it during the week, Patrick Vieira. Absolutely disgraceful."
Keane's former Manchester United team-mate Gary Neville echoed those sentiments as he added: "These last 20, 30 years we've bought the fences down in English football and supporters respect 99 per cent of the time that you don't go on the pitch. They enjoy the family environment.
"All of a sudden these last few months we've got idiots running on the pitch, but if you're attacking players and managers - what are you doing?"