One of six debutants in the squad, Walker will be locked in a four-way battle with Cameron Munster, Tom Dearden and Mitchell Moses for a spot in the Kangaroos' halves.
Walker is one of three Roosters premiership winners included, along with Clive Churchill medallist James Tedesco and prop Lindsay Collins.
Tedesco would have been a candidate to regain the Australian captaincy were it not for the fact Yeo has decided to delay going under the knife.
The Penrith lock played through the pain of a torn pec on his side's run to the preliminary final loss to Newcastle, and will lead the Kangaroos out in their group stage opener against New Zealand on October 16.
"There's no higher honour in the game than playing for your country … my plan all along was if I got back for Penrith and it was travelling alright then I'd leave myself open for selection," Yeo said on Monday.
"I needed the club to allow me to because it (playing the World Cup) will probably push (my return) into the start of next season.
"I've been up front and honest with Kevvie and it's feeling good and I would only put my hand up if I thought I could contribute and perform at the level that's needed for our country."
Among the more notable inclusions in Walters' squad are the returns of Tom Trbojevic and Latrell Mitchell, both of whom were denied further international caps by injury problems in recent seasons.
Mitchell's South Sydney teammate David Fifita is also in line for his first Australian jersey after previously playing for Tonga at Test level.
But the battles for a halves berth will provide the most intriguing narrative with Moses and Munster down on form in 2026 and Walker excelling for Queensland and the Roosters.
"That's the beauty of the Australian team is we have got some great options, and there's no right or wrong with who we select," Walters said.
"It's a matter of sitting down with our leaders, as well as myself and making sure we get the right people to play in the right positions.
"We took four away last year. I feel like they're really important and key positions so we want to pick the best players in those positions to play for Australia to cover everything."
Walters would not be drawn on whether Tedesco was his first-choice fullback with Reece Walsh also named in the Kangaroos squad.
Walsh was the star of last year's Ashes whitewash but missed the end of Brisbane's miserable premiership defence with an ankle injury.
"Reece is ready to go and looking forward to getting back in the green and gold, he's quite a player as well," Walters added.
Meanwhile, Newcastle fullback Kalyn Ponga will be free to line up for New Zealand against the Kangaroos after escaping with a $1000 fine for his high shot on Victor Radley.
Kangaroos squad: Bradman Best, Jack Bostock, Blake Brailey, Pat Carrigan, Lindsay Collins, Reuben Cotter, Tom Dearden, Tino Fa'asuamaleaui, David Fifita, Harry Grant, Keaon Koloamatangi, Liam Martin, Latrell Mitchell, Mitchell Moses, Cam Munster, Cam Murray, Jacob Preston, Kotoni Staggs, James Tedesco, Tom Trbojevic, Sam Walker, Reece Walsh, Isaah Yeo.
