Sam Walker's expected return for the Roosters, only four weeks after syndesmosis surgery, has revived his prospects of representing Australia.
Kangaroos coach Kevin Walters said Walker is "right back in the mix" if Nathan Cleary is unavailable for next month's World Cup.
Cleary remains Australia's preferred halfback, but a bone stress injury in his foot has created significant uncertainty.
Penrith said the injury resulted from overuse after Cleary suffered it during the NRL qualifying-final win over the Roosters.
The 28-year-old has been named against Newcastle in Sunday's preliminary final, though his training has been heavily restricted.
Walters told News Corp on Thursday that Cleary's World Cup selection would depend on his condition after Penrith's finals campaign.
"Nathan has been named to play this weekend and we'll see how he goes after that," the coach said.
"If the Panthers get through to the grand final, then I will play it by ear on how Nathan's injury is."
"Obviously if he's fit, he'll be picked for the World Cup, but there's a question mark over whether he'll be fit or not."
Cleary could withdraw to prioritise recovery, leaving Walker, Tom Dearden and Mitchell Moses competing for the halfback position.
All three are included in Australia's preliminary 40-man squad, alongside playmakers Cameron Munster, Ethan Strange and Matt Burton, with 23 places available.