Nuneaton Town manager Brian Reid has left the Conference club after only five months in charge.
Boro are now looking for their fourth manager since March after calling time on Reid's spell at Liberty Way.
The 43-year-old Scot signed a one-year contract taking him up to May 2015 when he took over from caretaker boss Mark Noon, who was in charge for a month after Kevin Wilkin's move to Wrexham.
Noon has again taken temporary control of the Conference strugglers.
He will be in charge for Tuesday night's home game against high-flying Forest Green.
"It's a decision taken by the board which we believe is the right thing to do," Boro chief executive Ian Neale told BBC Coventry & Warwickshire. "An agreement was made by all parties it could not continue in that way.
"Certainly there were some issues. But I don't think it would be right for the club or Brian to discuss personal matters. We've got to agree a deal with Brian over the settlement of his contract."
Reid only took charge of 10 Boro matches after taking over from Noon in April.
After losing their first game, they then finished last season unbeaten in their final two matches - and have struggled since last season's top scorer Louis Moult departed to join his old boss Wilkin at Wrexham.
They failed to find the net in their first five matches and, although they ended that drought by winning 2-1 at home to Altrincham, Saturday's 4-0 defeat at Torquay triggered a boardroom reaction.
"You could say it's my mistake," added Neale. "I appointed Brian, so I want to put it right."