Adam Clune, Shaun Sauni-Esau, Max Feagai and Mat Feagai are the new names to join the Dragons through their development program.
The Dragons now have completely filled their development roster spots by signing the quartet, following recent additions in utility Hayden Lomax and five-eighth Jayden Sullivan.
NRL development players train full-time with the Top 30 squad, but aren't available for first-grade selection before June 30. Jason Saab and Jackson Ford were 2019 NRL debutants who were examples of development program success.
"We use all six of our development player squad positions as it is part of our pathways' philosophy when it comes to our local juniors and our systems," Director of Rugby League Pathways and List Management Ian Millward told the club's website.
"With the advancement now of Jason Saab, Eddie Blacker and Joe Lovodua into our Top 30, we had positions within the squad to fill. All six of our development players have excitedly come through our pathways system and high performance unit.
Clune spent the offseason abroad in Kenya. The playmaker has been rewarded by Illawarra for his impressive premiership-winning-season with the NSW Canterbury Cup Dragons side.
"Adam came through our junior representative teams and Under-20s a number of years ago and has featured in Canterbury Cup since, where he's been one of the competition's prominent players," Millward said.
Sauni-Esau has a long-standing junior history which includes competing in the Canterbury Cup.
"2019 saw him kick it to another level and play a number of reserve grade games. Shaun is a genuine left centre – which is rare as most centres these days prefer playing on the right – so we're particularly excited about that," Millward said.
"In a full-time environment, he'll really blossom as he gets more experience playing against men."
Both outside backs, the Feagais (Max & Mat) also look to make their impact known in 2020.
"[Max and Mat] have had an unbelievable 2019. They're originally from Leeton but have been in our pathways since Harold Matthews and have advanced from there," Millward said.