Sayers, the leading wicket-taker and Player of the Year in last season’s JLT Shefﬁeld Shield, was 12th man for Australia in Tests against England earlier this summer but was overlooked for the initial squad for the four-Test series.
Bird suffered a hamstring injury last weekend playing for Tasmania against Queensland in Brisbane.
The Australian squad departs on Thursday and plays a three-day warm-up game from 22 February.
The ﬁrst Test begins in Durban on 1 March.
Confirmed ✅— West End Redbacks (@WestEndRedbacks) February 12, 2018
Chadd Sayers is heading to South Africa with the 🇦🇺 squad as Jackson Bird’s replacement pic.twitter.com/gqWN0EiLrG