Crusaders loose forward Jordan Taufua has signed a one-year extension while prop Michael Alaalatoa and Hurricanes finishers Wes Goosen and Vince Aso inked agreements through to 2020.
All four will ultimately have the All Blacks in their sights. Alaalatoa, born in Sydney, has opted to chase the black jersey rather than represent the Wallabies.
Taufua is understood to have turned down a substantial offer from French club Pau to stick around for one more season and continue chasing his All Blacks dream.
While Liam Squire and Vaea Fifita are ahead of Taufua in the pecking order, the blindside stocks are thinning out somewhat with Jerome Kaino and Brad Shields set to depart after this Super Rugby season.
"The Crusaders have been such a big part of my rugby career and after weighing up my options, it was clear that this is where I want to be. I still feel like I have a lot to contribute and I'm loving playing my rugby alongside some of the world's best players, who are also great mates, and a passionate coaching group," Taufua said.
"2017 was a special season but each campaign brings new ideas, new faces and a fresh challenge. So although a seventh season makes me one of the more experienced players in the group, I'm still thriving in this environment, learning more and more about my game and developing as a leader in the team."
The New Zealand Herald revealed Aso's signing last week, and Hurricanes team-mate Goosen, still just 22, is another superb prospect.
Hurricanes assistant John Plumtree, who will take over as head coach in 2019, was delighted to have the pair's signature for the next two seasons.
"There is a lot of competition out there for the sort of talent that these two guys have so it's great that they want to stay with the Hurricanes and continue to build on what they have achieved so far," he said. "They are definitely the kind of people we want in the future."