Tuesday's game between Altrincham and King's Lynn has been postponed by the National League due to a coronavirus "procedural error" at the Norfolk club.
King's Lynn full-back Aaron Jones caught Covid-19 "over the festive period" and has had no contact with players or staff since 22 December.
But an unspecified error to do with Jones' situation - which the club say "has now been rectified" - means their match at Altrincham will not go ahead.
An investigation is now taking place.
The National League is aware of King's Lynn's statement but declined to comment.
No other players or staff at The Walks Stadium are having to isolate as a result.