Fiji's World Cup opener against Cook Islands is scheduled for Newcastle on October 18, with Jacob Saifiti available after completing his suspension.
Saifiti was named in the 23-man squad coached by Mick Potter, which surfaced on social media and still requires eligibility and integrity clearances.
He received a four-match ban for a high shot on Warriors winger Luke Laulilii during Newcastle's 46-32 loss in round 26.
The Knights had a bye in the final round, then played all four finals, allowing Saifiti to serve his suspension.
His most recent appearance in one of his seven Fiji Tests was at the 2017 World Cup.
Saifiti's availability is especially valuable with star forwards Tui Kamikamica sidelined by illness and Viliame Kikau by an ankle injury.
Dolphins utility Kurt Donoghoe, the RLPA bench player of the year, can play lock or in the halves.
Wests Tigers winger Sunia Turuva and co-captain Api Koroisau bring big-game experience and flair.
Turuva could feature at fullback because teammate Jahream Bula is missing the tournament after post-season shoulder surgery.
Fiji reached the World Cup semi-finals in 2008, 2013 and 2017, losing to Australia each time.