NRL development players can now be selected from Round 1, instead of having to wait until Round 12 under the previous rule.
The change applies to PNG Chiefs signings Nixon Putt, Finley Glare, Gairo Voro and Morea Morea, all recent representatives of the national team at the Rugby League World Cup.
Putt has signed a development contract for 2028 and is due to return with the PNG Hunters in 2027.
All four are eligible from the Chiefs' first game and could earn promotion to the top 30 after strong pre-seasons.
Clubs must have 24 players signed by November 1 the previous year and 28 by Round 1.
Putt has played 17 Tests for the Kumuls, made more than 150 reserve-grade and English appearances, and has yet to play in the NRL.
He has been with the Central Queensland Capras since 2021.
General Manager-Football Michael Chammas said, "We're pleased to be able to bring Nixon into the football program, and we believe his experience and talent will be of great benefit for the team."