James Tedesco has been added to Australia's No. 22 for the World Cup final against New Zealand at Suncorp Stadium on Sunday night.
The Sydney Roosters captain is set to serve as an extended-bench substitute, with coach Kevin Walters choosing him after Latrell Mitchell became ill.
Mitchell, originally listed at No. 18, has a stomach bug and will miss the match, assistant coach Ben Te'o confirmed.
"It is tough for Latrell to miss out but unfortunately he has had an illness the last few days," Te'o said.
"Obviously Kevvie made the selection call that it was best off to bring Teddy in."
Tedesco has played once in the tournament, while Walters has preferred Reece Walsh at fullback.
The 2026 Clive Churchill Medal winner impressed at No. 1 in Australia's 36-22 win over Fiji and could replace Walsh if he is injured.
"All of the guys in the squad have been outstanding," Te'o said hours before kickoff.
"If Teddy hasn't been in the team he has been helping us prepare, and you just never know when your opportunity is going to come."