SYDNEY (Agencies) - Australia could make the most changes to its Test team since World Series Cricket as part of its bid to level the Ashes series in Perth. With Phillip Hughes and Steve Smith coming into the Australia top six, even if only two of Michael Beer, Mitchell Johnson and Ben Hilfenhaus are selected it would be the most changes from Test to Test within a series for 14 years, since between the Sydney and Melbourne Tests against the West Indies in December 1996. If all three are selected - which would likely force the axing of Brisbane hat-trick exponent Peter Siddle - the five changes to the Australian team would equal when Graham Yallop and four debutants were included for the series-deciding Test against India, in early 1978 at the Adelaide Oval. National selector Greg Chappell denied the mass changes were either a sign of panic from the selection panel or an indication it was turning more aggressively towards youth. We were always going to make changes in relation to different conditions. Thats significant because with five Tests in seven weeks we wanted to make sure we could get all our main bowlers through the series so that we had our best bowlers to pick from for each venue, he said yesterday. Former Test paceman Damien Fleming, however, insisted the prospect of the most changes to an Australian team for almost 32 years was certainly a bad thing. Youd want to pick your best XI for the Gabba and then not change it, unless theres specific horses-for-courses, as in swinging seam conditions or a raging turner, he said. Its not good and its certainly a concern, particularly the rotation of the quicks. Theyre not getting rotated because its team balance. I think a lot of the selections are [based on] hope. One of the four players who debuted in that match in Adelaide, WACA chief executive Graeme Wood, said the fact the Australia team won the match - and therefore the series - suggested mass changes could work as long as you pick guys that are in good form. There was certainly a high turnover for those couple of years [during World Series Cricket], but the fact Australia won the first two Tests and the got beaten quite easily in Melbourne and in Sydney probably [influenced selectors]. They probably had an eye on the West Indies tour too, which was four weeks post that Test match, he said. The guys were playing pretty good cricket at the time, were obviously young and enthusiastic and added a bit to the team. While selection panel chairman Andrew Hilditch has indicated left-arm finger-spinner Beer will play, Fleming said he would prefer an all-pace attack supported by all-rounder Shane Watson, with Smiths leg-spinners used only sparingly. Irrespective of the composition of the attack, Fleming said it was essential the squads premier swing bowler, Hilfenhaus, was recalled to bowl into the Fremantle Doctor breeze at the WACA Ground. Hilfenhaus has to play because he has to do all the hard work into the 'Fremantle. Ryan Harris was our best bowler in Adelaide so hell have to play, and hell also have to do some work into the 'Doctor, and then you have Johnson and Siddle to bowl down breeze, the former swing bowler said. 'If [the pitch] is devoid of grass and it looks a belter thats when Beer might come into the team. I wouldnt have thought theyre putting Johnson in the squad not to play, so Siddle might be in a bit of trouble. He might have to go, just as Hilfenhaus was unlucky to go in Adelaide. Since claiming six wickets on the opening day of the series at the Gabba the Victorian has been unable to take a wicket in his subsequent 54 overs. Hilditch did, however, cite him along with Harris as the best-performed pacemen in the loss at the Adelaide Oval. Fleming predicted 26-year-old Siddle would cope well if left out for the third Test. Where we rate Peter Siddle so highly is his character. Blokes love him because he gives 100 per cent, an Andy Bichel-type. Im sure hed be disappointed, but Id be disappointed if he happened to miss out and there was a bit in the pitch because hes had to do hard work on two belters [for batting in Brisbane and Adelaide], he said. Despite Australia being only one loss away from its first home Ashes defeat in 24 years, Fleming believed the absence of Stuart Broad for the rest of the series would give Australia a fast-bowling advantage over England. I do think its our best opportunity to win because Stuart Broads a big [loss]. If we get a pitch which is suited to fast bowlers Ill back our quicks against their quicks. Theyve got James Anderson, 21-year-old [Steve] Finn, whos been impressive, and [Chris] Tremlett, [Tim] Bresnan or [Ajmal] Shahzad - theyre not superstars, he said. 'If we can defuse the [Graeme] Swann factor and make it a bowl-out between the quicks Im backing our boys.