Gregor Robertson could miss the start of next season after an operation to correct an Achilles tendon problem.
The Chesterfield FC full-back suffered the injury during the Spireites 3-0 defeat at Hereford and underwent surgery on Monday.
Robertson (27) should be involved in pre-season training during the summer but it is thought his recovery will see him unavailable for the big kick off in August.
The Scottish-born player began his professional career with Nottingham Forest and spent two year with Rotherham United before he joined the Blues four years ago.
Last season he played 14 matches before he suffered a broken leg during November against Carlisle in the Johnstone’s Paint Trophy showdown at Saltergate.
It took him a year to recover from that injury and he made his return to first-team action in November in the FA Cup game at Harrow.
He has since played 14 times - either at left back or in the centre of defence - before he broke down at Edgar Street.