Millwall chief executive Steve Kavanagh has issued the following statement:
"I'm sure the promotion-winning feeling is beginning to sink in for everyone associated with the football club after what was an unforgettable day at Wembley on Saturday.
"To have achieved promotion via the Play-Offs in the same season we went on a long and physically draining Cup run says a lot about the strength of character, desire, determination and quality of Neil Harris, his coaching staff and the players.
"The chairman, the rest of the board and myself were delighted that so many supporters were there to enjoy a memorable occasion. Your backing all afternoon was tremendous and I know how much of a difference it would've made to the players out on the pitch.
"Unfortunately the sheer emotion of winning in that fashion spilled over for a small minority who ran on to the pitch after the final whistle. Arguments can be made about the strength of the security operation but ultimately people need to be responsible for their own actions, especially as it is of course a criminal offence to enter the field of play.
"In my relatively short time at this club I have already seen just how much hard work and commitment goes into enhancing the club's reputation and thousands upon thousands of our fan base undoubtedly did their part to further that at the weekend. But we cannot condone the actions of the few who just went that bit too far on this occasion.
"Our focus now turns to carrying out comprehensive plans throughout the club ahead of the 2017/18 Championship season, which I'm sure everyone can't wait to begin."