With reigning champions Australia due to play England in the semi-finals at Edgbaston on Thursday, Wade and Marsh have been added to the squad.
"If he (Wade) comes in, he has played a lot of global cricket, which is a real upside and he's in no doubt career-best form", Langer said. "We will get that (on Sunday)".
"The whole Australia A team is here if they need to be replaced". And, despite Australia comfortably making the semi-finals, there have been times in this tournament when the stuttering middle order has made Handscomb not being there look a misstep.More news: Two dozen deaths in tribal violence in Papua New Guinea
Langer said Wade was in "career-best form" and praised Handscomb's "excellent temperament". However, coach Justin Langer said that not only the new players but all the "22 guys on the park" will be in pressure.
Langer credited sacked high performance boss Pat Howard for setting up the Australia A tour of England, ensuring players were battle-hardened and in close proximity if required.
Though they still can not be bracketed among the "invincible" Australian teams of the past, trust them to rise to the occasion when the stakes are high.
Australian coach Trevor Bayliss was drafted in with the aim of guiding their bid for a first World Cup title.
South Africa captain Faf Du Plessis has tipped Australia and India - who will take on New Zealand in the other semi-final - to reach the showcase at Lord's on July 14. "It was an overhang into the Lord's game and then when we came here we managed to produce something similar to the cricket we have been playing over the last four years and that was really encouraging".More news: United Kingdom watchdog proposes to fine Marriott $124 million for data breach
Stoinis picked up a side strain in Australia's loss to India before he passed a fitness test ahead of the Bangladesh tie at Trent Bridge.
Handscomb initially joined the squad as a replacement for Shaun Marsh, who was earlier ruled out of the tournament with a broken forearm. It didn't just affect our cricket, it affected our country.
If you are looking for fun on social media during the ongoing ICC Cricket World Cup 2019, you do not need to go anywhere as the official account of Cricket World Cup is the most entertaining spot to jiggle your amusing bones.
"I feel like there's a very special thing just around the corner for us Australian cricketers and the whole Australian public, to be honest".More news: Penguins center Matt Cullen retires after 21 seasons | AP sports