"Maybe (Sergio) asked for too much money and they didn't want to match it. You just never know."
Moreno (15-5-1) recently returned to the UFC after being cut by the promotion in late 2018 when the future of the flyweight division was in doubt.
While out of the UFC, he signed a multi-fight deal with America's Legacy Fighting Alliance where he won a title. His fight in September was his fight back with the UFC.
While Moreno isn't as big a name as Pettis, he's still ranked higher than Kara-France and provides the type of test the Kiwi is looking for.
"It's a tough fight," Kara-France said. "We want to fight those top level opponents and take it step by step.
"I'm not really too fussed - if it's Sergio, if it's Brandon, if it's Henry Cejudo - it's just another person for me. I don't really take it personally at all, it doesn't really matter who I'm fighting as long as I get paid and I get on the cards that I want to."
Kara-France is in Melbourne this week as one of the UFC's guest fighters to attend UFC 243 at Marvel Stadium, which sees his City Kickboxing teammates Israel Adesanya, Dan Hooker and Brad Riddell fighting. It was the first time he had been brought to an event as a guest fighter and he said it was a sign of what the company sees in him.
"I know the UFC want to push me - I wouldn't be here if they didn't want to. To be here on fight week and not have the pressures of actually fighting is kind of nice."