Violence "devastated" Millwall
The Metropolitan Police have confirmed 14 fans were arrested, 12 from Millwall, following the ugly scenes that erupted at Wembley, with numerous fights starting in the end reserved for Millwall supporters.
Four police officers received minor injuries in the trouble, some of which was shown live on television.
Millwall have vowed to do all they can to root out the troublemakers, but are aware the reputation they have worked tirelessly to rebuild is in danger of being wrecked.
"As a club we are devastated by the scenes we saw yesterday, which are in danger of undoing much of the good work we have done to try and change the perception of the club," said a Millwall spokesman.
"We are trying to find the answers to what happened."
A spokesman said it could not provide a breakdown of which arrests were Millwall and which Wigan, but the two Wigan supporters were not involved in disorder with Millwall fans.
Four of the arrests were for affray, one for affray and possession of Class A drugs, one for affray and assault on police, two for public order offenses, one for assault causing actual bodily harm and possession of Class A drugs, one for a racially-aggravated public order offense, one for ticket touting, one for possession of Class A drugs, one for theft and possession of offensive weapon, and one for breach of a banning order.
The police spokesman said: "A number of lines of inquiry are being pursued.
"There will be a significant post-match review and further investigation will take place to identify those responsible for committing offenses."
The information is the latest stage of a combined investigation, involving the police, FA and Millwall aimed at finding out the reasons why yesterday's game attracted so much trouble.
There has already been criticism in some quarters for the evening kick-off time, which offered supporters the chance to consume an excess of alcohol.
Some Millwall supporters were seen drinking heavily in the car parks around Wembley two hours before the match was due to start.
Privately though, the FA do not feel this is a significant issue given the number of high-profile matches at the stadium that have had evening kick-offs, including, two seasons ago, a Manchester derby semi-final, and last year an all-Merseyside encounter.
In addition, Millwall featured in League One play-off finals in both 2009 and 2010 and both passed off peacefully.
It is for this reason that officials of the south London outfit do not believe the fact some tickets were put on general sale will prove to be significant in the trouble as they have adopted exactly the same procedure in the past.
The club were as astounded by the apparent sight of their own fans fighting with each other, which has led some to privately wonder whether there was a premeditated element to the disorder.
Millwall manager Kenny Jackett said: "I know how hard the directors have worked to give the club a good image in recent years.
"We've overcome many hurdles in that area. It has no part in football, it's not what people go to football for."
Millwall captain Danny Shittu said: "No players want that to happen. It was supposed to be a happy day, regardless of the result it was meant to be good day out at Wembley.
"I'm disappointed by it but as players we just have to keep doing what we do.
"At the end so many supporters showed they were there just to spur us on but it's disappointing to hear about such things happening on a day like that.
"It's a small minority but things like that should not be happening. It should have been a great day for both sides."
Defender Shane Lowry added: "Sometimes you get a minority, but we brought almost 32,000 fans and the majority were fantastic. They out-sung the Wigan fans and backed us throughout the whole game.
"It's disappointing to see incidents like that but the majority of fans have been fantastic this season."