Coomealla Wentworth Third Division cricketer Brian McKenzie was flown to Melbourne and underwent surgery after being struck in the head by a ball while umpiring the first innings of the match against Merbein South.
At the end of the over, the ball was thrown to the other end of the pitch and struck McKenzie in the side of the head.
In the lower grades of the Sunraysia Cricket Association, the batting team typically umpires the innings.
It is understood McKenzie briefly continued on the field but a short time later showed signs of concussion and was rushed to hospital for a procedure to release swelling, before being transferred to Melbourne for surgery.
SCA president Andrew Farlie said the association was collecting incident reports from both clubs involved and investigation should be finished in the coming days.