Last year England Netball became embroiled in a public stand-off with Mentor and Mkoloma, when they tried to prevent the pair from playing in the transtasman league.
With the short lead-in time to the July world championships, England Netball wanted their national players to remain in Britain, so they could attend regular squad camps.
Mentor and Mkoloma argued they would benefit more from a full season of ANZ Championship netball, where they would be exposed to the world's best shooters, week in, week out.
While England Netball eventually backed down for the sake of their world championship campaign, they appear to be taking a more hardline approach with their stars this year.
On the evidence of Sunday night's heavy loss to Australia, this policy is not only hurting the English programme, but international netball.
New Zealand coach Waimarama Taumaunu said she would have liked to have seen her side tested against a full-strength England team.
"It is disappointing they are not at full strength for this tour," said Taumaunu.
"It's always more testing for us when you're up against England's best, particularly Geva and Sonia. They provide some real challenges for us in that circle.
"When you've got those challenges, our shooters really have to steel themselves for that and be prepared to play above themselves."
Silver Ferns shooter Cathrine Latu, who played the opening half of New Zealand's 63-27 goal win over South Africa in Sunday's opener, said that while England don't have their top defenders for the series, they can't afford to be underestimated.
Eboni Beckford-Chambers did an impressive job of containing Australian shooter Caitlin Bassett in the first half of Sunday's match, with her unorthodox style causing the Diamonds attack some problems.
"[Beckford-Chambers] is definitely very athletic and she can get up for those high balls. She's also really aggressive and can wear you down, so we have to be ready to stand up to that," said Latu.
England were able to compete with Australia for much of the opening half of Sunday's match, but they appeared to tire markedly as the third quarter wore on under the relentless defence of the Diamonds.
Taumaunu said that while England's execution on attack fell away in the second half, their defence did a good job of ruffling the feathers of the Australians.
"The English were competitive in a pretty messy game, they managed to really get in amongst the Australians and force errors," she said.
But the question that will remain unanswered this season is how competitive England could be if they selected their best team.
Quad Series - leg 2
Tomorrow, Newcastle
8.30pm: Silver Ferns v England.
10.40pm: Australia v South Africa.
Previous results:
Australia 64 v England 40.
NZ 63 v South Africa 27.
