The second-half melee sparked by Ashley Williams at Goodison Park, which is being investigated by Merseyside Police too, saw a supporter in the Howard Kendall Gwladys Street End push OL goalkeeper Lopes in the head before hitting out at him again.
Everton have announced that supporter will be banned from their future games and UEFA has opened disciplinary proceedings against the Toffees for "aggressions by supporters against players".
Everton boss Ronald Koeman has been backed in to 1/6 to be next Premier League manager to leave after Thursday's 2-1 defeat.
In a statement issued on Friday, Everton said: "Club officials have reviewed the footage of an incident that occurred in the 64th minute of the game against Olympique Lyonnais where supporters towards the front of the lower Gwladys Street End became involved in a confrontation between players.
"We have identified one individual whom action will now be taken against. This will include a ban from attending future Everton fixtures and the club registering a formal complaint with Merseyside Police."
The force also addressed the skirmish by confirming they were looking into the matter.
Their statement read: "Merseyside Police can confirm officers are investigating following a disturbance on the pitch during a football match between Everton and Lyon at Goodison Park last night, Thursday 19th October.
"Detectives will be reviewing footage and speaking to witnesses to establish what, if any, offences have been committed."
They added anyone with information "which could assist the investigation" should contact them on 0151 777 4065 or Crimestoppers anonymously on 0800 555 111.
UEFA's charge against Everton will be handled by its control, ethics and disciplinary body on November 16 and there could further punishment from the governing body still to come.
There remains a possibility that captain-for-the-night Williams might be sanctioned for his role in a brawl he instigated by barging into Lopes.
Any charge would depend on what is included in referee Bas Nijhuis' report of the contest, with the Dutch official only booking the Welshman at the time.
Speaking to BT Sport 2 after Everton's 2-1 loss, Williams said: "'It's what happens, it's football. It is what it is.
''It's high emotions. We want to win the game, they want to win the game and stuff happens. That was just one of those times.''
