Millwall have sacked manager Steve Claridge after just 36 days, with Colin Lee replacing him as Lions boss.
Lee was initially wanted by Claridge in a coaching capacity
Claridge, 39, who had two spells as a player with Millwall, was only appointed as the successor to Dennis Wise on 21 June.
"The board believe it was in the best interests of the club that this move was made quickly prior to the beginning of the season," said a club statement.
Claridge is said to be "deeply disappointed and shocked".
Lee, who had been brought to the club by Claridge and has yet to sign a contract, admitted he was shocked at the dismissal.
He said: "Steve was going to ask them if I could help out with the coaching on a non-contract basis.
"I left Steve with (former chairman) Theo Paphitis and set off back to the Midlands after the game with Gillingham on Tuesday.
"Steve wanted to get the permission of the board to take me on, and the meeting ended with him being dismissed.
"But I have not done anything wrong, to Steve or to anyone else. It's not in my make-up."
The Lions drew 2-2 at home to Gillingham in a pre-season friendly on Tuesday, having been 2-0 down.
Claridge has overseen just four friendly games - two wins, a draw and a defeat.
The much-travelled striker succeeded Wise, who resigned in May due to differences with the incoming chairman Jeff Burnige.
But it has been a turbulent month at the club, with Burnige stepping down and several key players leaving the New Den since Claridge took over on 21 June.