Sturt captain Brad Davis is poised to make his first-class debut, joining Kelvin Smith and Elliot Opie in the squad as the replacements for injured pace bowler Daniel Worrall, Callum Ferguson and Tom Cooper.
SACA General Manager High Performance Tim Nielsen said:
“There had to be some changes, we couldn’t keep backing in the same players.
“We’ve been playing below expectations this season and we’ve wanted much more from our experienced players through the tougher moments.
“They are the ones we require to show the way, particularly when we have been without other senior players through international duties or injuries.
“The side has had far too many really poor patches that have put us under pressure and cost us opportunities to be competitive or be in winning positions.
“The three incoming players have all performed well in Premier Cricket and the Futures League and deserve a chance to impress in the last two Shield games.”
Davis, 29, has made three First Grade centuries for Sturt this season on top of making two hundreds in the Toyota Futures League earlier this season.
Smith, who has scored five First Grade tons for West Torrens this season among his 904 runs at an average of 129.14, played a Shield game before Christmas but was squeezed out of the side when captain Head returned last month.
Fast-medium Opie has played two Sheffield Shield games but has not appeared since the 2015-16 grand final.
Alex Carey and Adam Zampa are with the Australian limited-overs squad in India and Richardson has returned home after suffering a left side strain while on national duty.
Both teams will announce their final XI at the toss.
South Australia's 12-player squad
Travis Head (c)
Smith, Davis, Opie
Worrall (hamstring), Ferguson, Cooper (omitted)