Netball Australia selectors will on Thursday name the side for the showpiece tournament in Liverpool, England from July 12-21.

"We're definitely having a look in this last round to help us make final decisions," Alexander told AAP.

"I'd estimate we've probably got three-quarters of what we want but we're probably looking for that last quarter and there's always difficult decisions to make to make sure you get the balance right with the group.

"We want to give everyone an opportunity in this last round."

The Diamonds are looking to defend their 2015 crown but will field an inexperienced line-up with the international retirement of the likes of former captain Laura Geitz (71 caps), Sharni Layton (46), and Madi Robinson (61).

Just skipper Caitlin Bassett, from the current squad, has more than 50 international caps to her name.

The 12-players selected are expected to come the 19-person training squad although Alexander said that wasn't a firm rule.

She said selection wouldn't be based purely on Super Netball performances this year but current form could help sway selectors.

Without giving away too much Alexander said she was pleased by the form of many players.

The long-term coach, who is signed until the end of 2020, said the Diamonds' midcourt shaped as the most hotly contested area.

Squad members Gabi Simpson, Liz Watson, Kim Ravaillion, Kelsey Browne, Kate Moloney, Jamie-Lee Price, Paige Hadley and Jess Anstiss are all in in contention.

"The centre court is going to be the hardest position to choose, not just because you've got to get that positional balance right, but you've got to try and pick players who are in form and also players who combine well and give us that balance in case there's injuries in Liverpool," she said

"It's going to be tough and there's going to be some really great players who miss out."

Australian Associated Press