Handscomb, who has struggled for runs and technical consistency against the plans and accuracy of England's James Anderson in particular, may find himself left out in favour of Marsh for reasons of team balance. A fifth bowling option is thought to be necessary on what has this season been an unforgiving Perth surface for bowlers.
While Nathan Lyon has performed commendably in the first two Tests as both an attacking and holding option, soaking up overs to keep Mitchell Starc, Josh Hazlewood and Pat Cummins fresh, the likely WACA surface, Marsh's return to the bowling crease and Handscomb's current malaise all point towards a change being made.
"We've got all the reports back and JL [Western Australia coach Justin Langer] has been really impressed with him," Lehmann said in Perth as the Australian team assembled. "He's surprised by bowling a couple of games ago, he surprised us as well to be perfectly honest. His batting has been exceptional all summer and he's led from the front as captain. He deserves his chance.
"Other people might be unlucky to miss out but Mitchell fills the role we need for this particular Test match. As a batter he was in some good form. But we needed his bowling as well. Now he's bowling, we can consider him."
Much as the captain Steven Smith had factored preservation of the bowlers in his decision not to enforce the follow on against England in Adelaide, Lehmann said the team composition for Perth would take into account the pitch, weather and the freshness of the pace bowlers. Jackson Bird is the other bowling member of the squad.
"It depends on the wickets, we'll just wait and see. They said it's going to have some pace and bounce in it, a bit like the old WACA," Lehmann said. "It's pretty hot this week so we'll have a better idea probably on Tuesday/Wednesday of what we're going to go with.
"We just want to have the ability to get 20 wickets. So if the three and Nathan can do that so be it. If we decide to go with an extra one it would be for that reason. You'd love to be able to make them available for all Test matches and all one-dayers. End of the day we just don't know how they're going to travel. At the moment our focus is just this game, so we can't look too far ahead or behind."
England's recent disciplinary issues, the latest the suspension of Ben Duckett for pouring a drink over the head of Anderson at the same Perth bar where Jonny Bairstow headbutted Cameron Bancroft, were not a source of mirth for Lehmann, who said it was vital that his players did not underestimate the tourists despite the current impression of off-field chaos.
"I've been through all that, so no, I don't have a chuckle," Lehmann said when asked if he had laughed at England's troubles. "You have those situations at various stages throughout your career. It's not funny. It's a case of actually making sure you're trying the best you can to get your side prepared. For me, I don't have a chuckle at any of that.
"Start from scratch, don't you, the first ball in Perth. For us we can't worry about what's going on outside with England. They're still a good cricket side and have some dangerous players. For us they've got to be really switched on come day one in Perth. Hopefully a crowd's there and we have a great spectacle over five days.
"For us we're going to have to play some really good cricket again. We've done that over the first two Test matches in periods of time and they've fought back in periods of time as well. We've got to start the game well and get in front of the game is going to be key."
As for the WACA's last Ashes Test, Lehmann said there would be plenty of nostalgia both inside and outside the dressing room for a venue that first hosted a Test match against England in 1970-71 but is now to be superseded by the new multi-purpose stadium across the Swan River at Burswood. Lehmann has mixed personal memories of the ground, coaching an Ashes win in 2013-14 but also being dismissed there by his brother-in-law, Craig White, in 2002-03.
"Not my brother getting me out in an Ashes Test match," he said when thinking of a favourite memory. "Winning the Ashes a few years ago in Perth. But the best one would be Viv Richards and Dennis Lillee in the Gillette Cup semi-final [in 1976]. It's on Facebook all the time. I watch it. It was a ripper. You hear all the stories about the pace and bounce and carry. It would have been fantastic to be part of that era.
"I'm pretty biased with the Adelaide Oval stadium. But walking past this stadium, it looks bloody good. So I expect it will be a great spectacle when it moves. Hopefully we can send off this ground in the right format with a win."