Walsh starred in Australia's two-point win over New Zealand, scoring a solo try and stopping Kalyn Ponga with a crucial tackle.
James Tedesco will play his first Test in three years when Australia meet Fiji in Brisbane on Sunday.
He was left out of the opening side in favour of Walsh, giving coach Kevin Walters a major selection decision.
Since 2023, Tedesco has reclaimed his NSW jersey, won last year's Dally M and earned the Clive Churchill Medal as Roosters captain earlier this month.
"But it's not a competition. I've got an opportunity and all I can do is make the most of it and do my role." Tedesco said.
Mitchell Moses has been ruled out with a calf injury, while Cam Munster is expected to be rested and Sam Walker and Tom Dearden will form a new halves pairing.
Moses's absence may favour Walsh, whose long kicking game is an option Tedesco does not provide.