Former Chelsea defender David Stride had been in charge of Southern League Bashley for just 40 days.
The New Forest club's newly appointed board have named former manager Steve Riley as Stride's replacement.
"It's absolute codswallop. The club already had someone in mind to replace me, but waited two weeks before telling me," Stride told BBC Sport.
Bashley have lost all four of their pre-season friendlies so far, failing to score a goal and conceding eight.
Stride, 57, had only been in charge for two of those matches.
"We made a tough decision to change things around now rather than the possibility of having more upheaval during the season," chairman Tim Allan said.
Stride made 35 appearances for Chelsea between 1978 and 1980 and also played for Leyton Orient and Millwall in the 1980s.
He was appointed by Bashley on 17 June, but five and a half weeks later and after a change of club chairman, he is out of work.
"I've got no hard feelings, but sadly the club weren't man enough to tell me earlier," Stride added.
"I was given the guarantee I'd be left alone for a season to take sole charge of football matters, but I'm gone after just two games."

Northern Constabulary have named the man as Daniel Maddox, 41, who was from Clackmannanshire.
Emergency services were alerted to the incident at an "off-piste" skiing area in the Etive Glades on Saturday.
Glencoe Mountain Resort said the experienced off-piste skier had been caught in a major avalanche.
Northern Constabulary co-ordinated the search, with members of Glencoe and Lochaber rescue teams.
Mr Maddox was found at about 12:00 on Sunday, in 18-20ft of snow.
Lochaber Mountain Rescue Team said they would like to extend their thoughts to the family of the dead man.
The searchers were assisted by an RAF Lossiemouth helicopter.
John Grieve, leader of Glencoe Mountain Team, said the avalanche travelled about 1,000ft down the slope's rocky face.
"The avalanche has actually gone into a gully, and in some places the snow is about 40ft deep," he said.
There have been a number of serious incidents as a result of avalanches in Scotland this year.
In January, four experienced climbers died on Bidean Nam Bian in Glencoe.
Three people also died after an avalanche in the Cairngorms in February.
Two of the climbers were off-duty members of the RAF Mountaineering Association. The third fatality was a student on a course at the Glenmore Lodge outdoor centre.
In the same week there was a second fatal avalanche involving a hillwalker.
A non-league manager has been sacked for "a run of poor pre-season results and lack of player signings".
[NEXT_CONCEPT]
Searchers have found the body of a skier who went missing in an avalanche near Glencoe Ski Centre in the west Highlands.