Steve Eyre has been appointed assistant to Chesterfield manager manager Gary Caldwell.
Eyre had joined the backroom staff on a short-term contract in February.
Spireites director and company secretary Ashley Carson said: “Steve has impressed us very much with his great knowledge and enthusiasm.
“Gary Caldwell was keen to ensure that Steve remained at the club and we are delighted that he has agreed to stay.”
Eyre spent 21 years with Manchester City, winning five youth league titles and the FA Youth Cup.
He managed Rochdale in 2011 and was later senior professional development coach at Huddersfield Town.