The Football Association has launched an investigation into the crowd trouble during Millwall's League One play-off semi-final clash at home to Leeds United.
Several home supporters came onto the field following Neil Harris' winner in the 71st minute with the FA now planning to make further enquiries and gather information on the incident at the Den.
Leeds goalkeeper Casper Ankergren was taunted by the Millwall fans after the goal and also had objects thrown at him, with Scotland Yard later confirming that one man had been arrested on suspicion of assault.
The FA's decision to look into the incident comes on the back of the Danish goalkeeper's plea for action to be taken against the London club.
"There was something thrown at me, I didn't see what it was as I turned my back on it," he said.
"It's very bad for football and Millwall should be punished.
"I was pushed in the back by one of the fans that came on the pitch too. It should never happen, fans should not be allowed on to the pitch.
"I'm not sure what the security were doing as no-one came to remove them. They are meant to be here to protect the players, it's not good enough.
"Anything could have happened, luckily it didn't and hopefully I wouldn't experience that again.
"English fans are normally much better than Danish fans, who always throw stuff on the pitch and at players.
"But it's happened here at Millwall and I hope something will be done. It is a disgrace to football."
Millwall have confirmed that any fans arrested will be banned from all their games for the foreseeable future and that Ankergren has received apologies from the club.