The Latics lie 18th in League One after a run of four consecutive defeats, the latest of which came at home to Crewe on Saturday.
Following weekend discussions between Dickov, chairman Simon Corney and Oldham's directors, assistant manager Gerry Taggart, reserve boss Lee Duxbury and fitness coach Paul Butler have been removed from the management team.
A decision on the future of goalkeeping coach Paul Gerrard, who will assist Dickov for Tuesday's trip to Scunthorpe alongside head of youth Tony Philliskirk, has been delayed.
A statement on the club's official website read: "The board is concerned with the bad run of results and understands the frustration of fans to the point where it realised that positive action needs to be taken.
"With immediate effect, assistant manager Gerry Taggart, sports scientist and fitness coach Paul Butler and reserve team coach Lee Duxbury will be placed on gardening leave and will take no further part in the club's plans for the future.
"The position of goalkeeping coach Paul Gerrard will be considered at a later date. He will assist the manager in the immediate future."
As part of the statement, Corney offered personal backing for his manager.
He said: "We appointed Paul Dickov in June, 2010 and it has been a vast learning curve for him.
"He has received mine and the board's support along the way because we believe that we have the right man on board.
"However, in recent times we, as a board, are unanimous in the belief that the chemistry of our backroom team and coaches is not right and this has been discussed with Paul in depth.
"I thank those members of staff who are leaving for their commitment and support in the past, but believe that changes are necessary for the good of the club."