Smith explains Clarke spray

Australia batsman Steve Smith admits he was as surprised as anyone when he copped a rocket from skipper Michael Clarke for being too friendly in the recent Test series against Pakistan.

Smith was told to zip it by Clarke after being seen talking to Pakistan batsman Azhar Ali at the non-striker's end during the opening day of the second Test.

However, Smith revealed on Monday that he was actually trying to unsettle Ali rather than have a friendly chat with the batsman.

"I was actually getting into him," Smith said.

"So it (the spray from Clarke) wasn't what I expected, but that happens I guess.

"We like to play good, hard, tough, aggressive cricket when we're out in the field. That's the way we like to play, so we'll continue to do that."

Smith was a rare shining light for Australia during the 2-0 series loss, with the 25-year-old scoring two half-centuries, including 97 in the second Test.

The part-time spinner will be back in action this Friday when he lines up for Australia in the opening one-day clash with South Africa at the WACA Ground.

Star Proteas allrounder JP Duminy will miss the five-match series due to a long-standing knee injury that flared up during his team's series-deciding T20 loss to Australia on Sunday night.

Duminy has been replaced by Farhaan Behardien in the squad, while fast bowler Marchant de Lange has also been called up.

Smith said the one-day series would give players a chance to cement their spot in the side ahead of next year's ICC World Cup.

"I think they are trying to get the team that they will be playing in the World Cup and there's not too many games before then," Smith said.

"There's plenty of work to do and all of the boys are trying to get a spot in the team."

Calls are growing for Smith to bat at No.3 in the Test team after Glenn Maxwell and Alex Doolan failed to fire in the United Arab Emirates.

Smith has enjoyed most of his success batting at No.5, and he said he wasn't bothered where he bats in the order.

"I am happy at the moment wherever I am batting to be honest," Smith said.

"That's up to Michael and the coaching staff I guess.

"For me, it's about batting wherever I am told and trying to get as many runs and win games for Australia as I can."

Australia squad: Michael Clarke (capt), George Bailey, Nathan Coulter-Nile, Aaron Finch, Josh Hazlewood, Mitchell Johnson, Mitchell Marsh, Glenn Maxwell, Kane Richardson, Steve Smith, Matthew Wade, David Warner, Shane Watson.

South Africa: AB de Villiers (capt), Hashim Amla, Quinton de Kock, Faf du Plessis, David Miller, Ryan McLaren, Kyle Abbott, Dale Steyn, Wayne Parnell, Morne Morkel, Robin Peterson, Imran Tahir, Farhaan Behardien, Marchant de Lange, Rilee Rossouw, Vernon Philander.