Southby has left the door open for the young pair to return to the squad later in the year ahead of the international season, filling just 14 of a possible 18 contracted positions.
The big winners in today's naming are young midcourter Gina Crampton and defender Storm Purvis, who previously played under Southby at the Southern Steel, along with Tactix defender Jess Moulds.
Experienced defender Anna Harrison also makes her return to the national squad following the birth of her second child.
Silver Ferns coach Janine Southby says the squad is an exciting blend of youth and experience.
"I've been impressed with what I've seen this week. Obviously there's still a long way to go and we'll start bedding down some new structures and plans in January, but we've selected an exciting mix of athletes," Southby said.
"We are at the start of a new four-year cycle, so while we are looking ahead to those major events it is important that we continue to build on the platform that was set this year."
2016 Silver Ferns Squad
Bailey Mes, Cathrine Latu, Maria Tutaia, Ameliaranne Wells, Gina Crampton, Kayla Cullen, Shannon Francois, Laura Langman, Grace Rasmussen, Leana de Bruin, Katrina Grant, Anna Harrison, Jess Moulds, Storm Purvis.
2016 National Development Squad
Ellen Halpenny, Phoenix Karaka, Malia Paseka, Erikana Pedersen, Te Paea Selby-Rickit, Samantha Sinclair, Sulu Tone-Fitzpatrick, Zoe Walker