Australia yesterday recalled veteran fly-half David Knox to their squad for this weekend's TriNations rugby union test against South Africa in a remarkable change of heart by coach Greg Smith.

Knox will interrupt a playing stint with South African province Natal to join a 22-man Wallaby squad for Saturday's Brisbane test after Tim Horan was ruled out with a broken hand.

Australia are to make at least two other changes from the side beaten 33-18 by New Zealand on Saturday after dropping back rower Michael Brial and losing full-back Matt Burke to injury.

Smith has repeatedly cited Knox's lack of defensive strength as the reason behind his decision to ignore the ACT Brumbies' goalkicker this season.

But in a sudden turnaround yesterday, Smith said in a statement: "With the injury to Tim Horan's hand, Knox is an automatic choice for the Wallaby fly-half position."