Australia's hat-trick hero Peter Siddle could be dropped for the third Ashes Test in Perth.

Ian Healy and Kim Hughes are leading a chorus of discontent about omitting the Gabba hat-trick hero from the third Test against England.

"I would not agree with dropping Siddle," former Australia wicketkeeper Healy said.

"I am a big advocate for continuity. Three weeks ago Siddle was, with the others, given the responsibility of winning back the Ashes and now that could be taken away from him.

"I am sure every out-of-form player would love to have a two-week break, but what they have done has put a lot of pressure on him. What happens if he fails?"

Healy's comments come after national chairman of selectors Andrew Hilditch gave a strong indication that rookie spinner Michael Beer will be handed a debut in Perth.

However Australia captain Ricky Ponting said the Aussies should at least consider playing four quicks at a ground that has historically favoured fast bowlers.

Siddle was reduced to the role of spectator at training on Tuesday as Johnson and Ryan Harris bowled in the middle of the WACA Ground, then looked on as the pair joined Ben Hilfenhaus in the nets.

Siddle's hat-trick on day one of the first Test, coupled with his first-day return of 6-54, appeared to have shored up his place for the series.

On Monday, Siddle smashed Ricky Ponting's protective box and left the Test captain gasping for air in the nets, but Johnson is likely to beat him for a place in the XI.

Siddle has gone wicketless since his six-wicket haul in the first innings of the first Test, but bowled infinitely better than his 0-121 in Adelaide suggested.