Forfar Athletic say they are "disappointed by the timing" after Stuart Malcolm and his management team resigned with their side sitting bottom of League 1 with seven games left.
The decision by Malcolm and assistants Barry Sellars and Martyn Fotheringham followed Thursday's 3-0 loss to Clyde.
It leaves Forfar five points adrift of Dumbarton, who beat East Fife 2-1.
Defender Gary Irvine, 36, will take charge for Saturday's home game with East Fife.
"The directors had no option but to reluctantly accept their decisions," Forfar said in a statement.
"But we are disappointed with the timing, especially taking into account the hectic schedule of games the club have ahead of them especially in the next seven days and beyond."
Former Ross County and Arbroath defender Malcolm, who had two spells with Forfar as a player, had been in charge at Station Park since 2019.
Forfar, who play their fourth game in seven days when they entertain East Fife on Saturday, have reached the last 16 of the Scottish Cup after beating Lowland League Linlithgow Rose after extra time and Edinburgh City on penalties.
However, they have won just once in their last nine league games after a first-half double from former Scotland striker David Goodwillie and a Craig Howie strike early in the second half moved third-bottom Clyde six points clear of the visitors with a game in hand in Cumbernauld.