Siddons and the SA Cricket Association describe the parting as a mutual agreement after another failed Sheffield Shield season for the Redbacks.

Siddons had been SA's coach for the past five years.

"Unfortunately the Redbacks have not been performing to our expectations in recent seasons," SACA chief executive Keith Bradshaw said in a statement on Wednesday.

The Redbacks played in two losing Shield finals in Siddons' initial two seasons, but since have failed to make an imprint on the four-day competition.

In the middle of this season, Siddons took personal leave from his role.

He will be replaced by ex-Australian batsman Greg Blewett for SA's last Shield game this season, against Queensland from next Tuesday.

Australian Associated Press