Australian netball coach Lisa Alexander insists Sharni Layton's Commonwealth Games aspirations remain alive, but that the window is slowly closing for Laura Geitz.
Defender Layton was slated to return from exhaustion for the Diamonds' Quad Series tour of England and South Africa in January, but on Friday was cut from the squad after failing to gain medical clearance.
The 29-year-old has returned to pre-season training with Super Netball outfit Collingwood and was initially named to return for the Diamonds' final hit-out before April's Commonwealth Games.
Alexander said Layton remained in the frame for next April's Commonwealth Games, but that playing in the Quad Series was deemed too risky.
"She's progressing really well, but she wasn't able to complete the full rigours of training that we require at the time we require," Alexander told AAP.
"She could put herself at physical injury risk if she's not at that level."
Fellow leadership candidate Madi Robinson has again been left out of the side, but will join Layton in a four-day Commonwealth Games simulation camp in January to press her case for a late Games call-up.
"That mid-court race is wide open, but it would be hard to leave anyone out (from the current squad)," the coach said.
Alexander said former captain Geitz, who is returning to the sport after having her first child, was an outside chance of attending that camp.
"We'll keep monitoring her," Alexander said.
"It's week to week with Geitzy and not as likely that she'll be there, but you would never count her out."
Alexander said Layton's case was not unusual, citing Geitz and retired Catherine Cox as others to have needed some time off during their careers.
"We've been managing that (burn out factor) for quite a long time, ever since the ANZ Championship came in (in 2008)," she said.
"It's always tough to get the balance right and we're never happy if it happens but it's a multi-factorial thing and you've got to be cognisant of that."
"I'm just happy to see that Sharni is getting better."
The Diamonds squad will gather in Canberra from January 11-14 for the camp, before the 14-strong squad depart for games against New Zealand, South Africa and England in London and Johannesburg.
Diamonds squad: Caitlin Bassett, April Brandley, Courtney Bruce, Paige Hadley, Emily Mannix, Kate Moloney, Susan Pettitt, Kim Ravaillion, Gabi Simpson, Caitlin Thwaites, Gretel Tippett, Liz Watson, Jo Weston, Stephanie Wood.