Tyrone man Boyd Rankin could make his Test debut for England in the final Ashes clash in Sydney, with the visitors looking to avoid a humiliating 5-0 whitewash.

The match begins tonight (11.30pm Irish time) and the 6’8 fast-bowler, who followed in the steps of Eoin Morgan by switching allegiance from Ireland in the hope of playing Test cricket, is one of three potential debutants, alongside batsman Gary Ballance, and leg-spinner Scott Borthwick.

"It's possible, yes” said England captain Alastair Cook, when asked about changes to the line-up.

"Settled sides happen when you win games of cricket and perform well.

"When you lose games of cricket and people's performances don't justify selection, then there's going to be lots of changes."

Cook added: "We want to start with a win here. It gives people who might not have played in this series the chance to make a difference.

"They can think that if they score a hundred here...they'll get to play another Test and try to make a difference."

Meanwhile, Australia captain Michael Clarke is prepared to put pragmatism before romance in order to inflict a whitewash on England.

Clarke acknowledges the temptation to try to field an unchanged, winning team throughout the Ashes series, which concludes in Sydney.

But he knows too that Australia's selectors will not do so without first assuring themselves those same 11 players who proved too good for England in Brisbane, Adelaide, Perth and Melbourne are the same ones best suited to prevailing conditions at the SCG.

With all-rounder Shane Watson able to bowl in the nets, despite the groin trouble he had in Australia's victory in Melbourne last week, even on a 'greentop' the hosts can therefore have four seam options - leaving room for off-spinner Nathan Lyon to be retained.

"Settled sides happen when you win games of cricket and perform well." - Alastair Cook

Clarke said: "I think it would be extremely romantic [to stick with same team].

"But you've got to pick the best 11 players to help you have success in the conditions you're playing.

"If conditions turn out to be similar to what they have been in the past four Test matches, then I think the selectors will go that way."

"That's as much grass as I've seen on an SCG pitch.

"Looking at it today, I think it would certainly suit the fast bowlers, but ... I think the forecast is pretty warm for the week, so I still believe spin will play a part throughout the Test match."

Clarke can empathise with the tourists, having led his team to a 3-0 series defeat in England just last summer.

"When you're not performing well as a team, [everyone] seems to notice everything," he said.

"When you're winning, you get away with murder. Everything seems to be covered over. You don't mean to drop catches; you don't mean to make no runs.

"We all get out of bed every day and train as hard as we do to try to perform - but it's a tough game."

"I've copped a fair bit of stick, but even through that time I've had a lot of support from family and close friends.

"That's what probably makes this series so special to the team and me personally - a thank you to the people who have supported us."

It will be all the sweeter for him then if Australia can win again here, and he is confident he has the right men on his side to help them do that.

"I think that desire burns within every single player in the changing room," Clarke said.

"I think we showed (that) with the way we played at the MCG. This Test is no different."