Ken Bates has revealed the future of Simon Grayson came to a head when the former Leeds United manager wanted to add another midfielder to the squad.
Grayson was sacked by Leeds last month following a 4-1 home defeat by Birmingham City after three years in charge at Elland Road.
Neil Redfearn has been in placed in caretaker control of first-team affairs as chairman Bates takes his time to decide upon Grayson's long-term successor.
Bates has now outlined one of the reasons behind his decision to part with Grayson following the request to sign a midfielder in the January transfer window.
"It came to a head when Simon wanted to sign a midfielder which would have cost the club nearly £1.5million over the length of his proposed contract," wrote Bates in his programme notes for Saturday's 2-1 home defeat by Brighton & Hove Albion.
"We already have nine midfielder players, so I refused - the first time ever!
"The current first-team squad is 28 strong. Premier League clubs are only allowed to register 25.
"In the circumstances it was decided to part company with Simon and his staff immediately following the Birmingham result."