While the uncapped Weatherald is not assured of his place at the top of the order for the opening match in Perth, the significance of being selected in Australia's 15-man squad was not lost on the 31-year-old.
"It is a pinch-yourself moment," he said in Hobart on Friday.
"As a kid in Australia, you grow up wanting to play professional sport; representing Australia in cricket is the highest honour, and something that I've aspired to my whole career."
Khawaja had singled out Matt Renshaw as his preferred option to open alongside him, but when his Queensland teammate did not make the squad he subsequently backed Weatherald.
"He didn't have me in four days ago," quipped Weatherald, whose rich form in domestic cricket prompted his Ashes section.
"You get the backing of someone like that who's played so much first-class cricket, so much test cricket.
"He's made so many hundreds for Australia and is such a respected cricketer within our community.
"I'd be really excited to partner up with him at some point."
Speaking to Fox Cricket on Thursday, Khawaja had praised Weatherald's consistency.
"I've played a lot of cricket against him ... he's a terrific player. Conditions last year were pretty hard at Shield cricket, and he was a standout," said the 38-year-old.
Australia are hoping all-rounder Cameron Green can bowl his full quota, which would allow them to slot him in at number six and clear the decks for Weatherald and Khawaja to open with Marnus Labuschagne at his preferred number three position.