Former Town boss John Duncan is seriously ill in hospital.
The Scot, now 73, was manager of the Blues between June 1987 and May 1990, recruited from Chesterfield following Bobby Ferguson’s departure.
A forward with Dundee, Tottenham, Derby and Scunthorpe during his playing days, Duncan rejoined the Spireites three years after leaving the Blues and famously took them to the FA Cup semi-final in 1997, eventually losing to Middlesbrough in a replay.
Early in his career he had spells as manager with the Iron and Hartlepool and later worked at Loughborough University.
Duncan’s former Chesterfield player Phill Walker announced the news on Twitter with the Spireites, ex-Blues midfielder Simon Milton and Town sending their good wishes.