Australia will not look outside their 17-man Ashes squad when picking an XI for the fifth Test.

However, Darren Lehmann acknowledges there are tough calls to be made on the touring party following the dead rubber.

Australia are a team in transition.

Managing that process of blooding youngsters and dealing with the twilight moments of so many careers is Lehmann’s biggest challenge amid the fallout of a failed campaign to retain the urn.

“There are going to be tough calls somewhere, we’re not afraid to make the tough call,” Lehmann said.

“But you’ve got to also look after Australian cricket in the right way.

“We’ve got to make sure we’re doing the right things by the players, both old and new.

“We just need to sit down and think about that, how we want to go about it.”

Already, Michael Clarke and Ryan Harris have retired.

Chris Rogers has previously said he will do the same, but the opener has been the side’s best-performing batsman in the five-Test series.

Lehmann wasn’t keen to look beyond next week.

Australia start a three-day tour game in Northampton on Friday.

The final Test follows at The Oval, starting on Thursday week.

Joe Burns and Glenn Maxwell, two young players to have already donned the baggy green, hit timely centuries as Australia crashed to an innings and 78-run loss at Trent Bridge.

However, Lehmann confirmed he and chairman of selectors Rod Marsh would not be summoning any players from outside the 17-man squad.

“We’ll pick the best XI to win that Test match once we’ve seen the wicket,” he said.

Mitch Marsh will presumably be recalled after Lehmann admitted the allrounder’s omission was an error.

Selectors may opt to give Shane Watson and Brad Haddin swansongs.

Regardless of the XI, Lehmann was confident his charges would be competitive in the dead rubber.

“I’m actually looking forward to the last Test,” he said.

“I think it’s going to be a great last Test match.

“We’ve got to try to get a result there.”

Australia’s next Test assignment after the Ashes is a short tour of Bangladesh in October.

A home three-Test series against New Zealand follows, with the inaugural day-night Test to heighten interest in the trans-Tasman tussle.