The Wallaroos coach insists the inclusion of sevens players can only benefit the 15-a-side national team as players eye the World Cup.
Jo Yapp revealed on Tuesday the 40 players in an extended squad to face Fiji on May 3, including three who have left the country's globetrotting sevens team to chase 15s success.
Charlotte Caslick, Tia Hinds and Bienne Terita have foregone sevens duties and made themselves available for Wallaroos selection in the hope of playing in the World Cup in August.
Yapp said the sevens stars' inclusion has pushed the 15s specialists to up their game.
"We've been really clear with the players throughout all of this, so they recognise that for us to be successful, we want to take the best players to the World Cup," Yapp said.
"Even just knowing that these players are putting their hands up, we've seen real growth in our girls because competition for places is there."
The coach also hinted other sevens players could be added to the squad once their world championship duties were over.
That includes superstar Maddison Levi, who is yet to play 15s rugby after a thumb injury kept her from a Reds debut alongside sister Teagan.
Yapp said Levi's inexperience at 15-a-side level would mean she would not be rushed straight into the playing side.
"Ultimately, we want to make sure we're setting Maddi up for success," Yapp said.
"So just bringing her straight in to play a Test match without any real 15s exposure or experience, because obviously unfortunately she missed out on the Super W, wouldn't be fair on her."
"So if we bring her in we need to give her opportunities to train with the team first."
The Fijiana Test is one of seven before the World Cup in England from August 23.
Yapp confirmed the players who had elected to stay with the sevens team for their world championship in Los Angeles on May 2-3 would not be available for Wallaroos selection until their game against the USA on May 17.
The Wallaroos coach said the first goal would be to get the team prepared to get out of their tough group at the World Cup in England, which includes the hosts, USA and Samoa.
* WALLAROOS SQUAD
Katalina Amosa, Ruby Anderson, Bree-Anna Browne, Charlotte Caslick, Emily Chancellor, Lori Cramer, Annabelle Codey, Biola Dawa, Waiaria Ellis, Ashley Fernandez, Georgina Friedrichs, Martha Fua, Caitlyn Halse, Zoe Hanna, Tia Hinds, Eva Karpani, Lydia Kavoa, Kaitlan Leaney, Michaela Leonard, Ashley Marsters, Arabella McKenzie, Desiree Miller, Tiarah Minns, Faitala Moleka, Manua Moleka, Tiarna Molloy, Layne Morgan, Tania Naden, Alapeta Ngauamo, Bridie O'Gorman, Siokapesi Palu, Faliki Pohiva, Trilleen Pomare, Ella Ryan, Cecilia Smith, Maya Stewart, Adiana Talakai, Bienne Terita, Tabua Tuinakauvadra, Natalie Wright
