Date of birth
Harness switched from Burton Albion to the Blues ahead of the 2019/20 season.
Harness joined Burton from Coventry as a teenager and gained experience with several loan spells, most recently spending a season with Port Vale.
He made a total of 83 appearances for the Brewers and scored a hat-trick in their 4-0 victory at Rochdale last term.
Harness was part of the Burton side that were narrowly beaten by the Blues on home soil back in April.