McLeod said questions needed to asked around why players, such as Northland's Sam Harrison, were feeling burned out at age 21.
"There's huge pressure, we currently have a ranking of third for the woman and, prior to the Olympics, we were sixth. It's the goal of Hockey New Zealand to be in the top six and win medals, so the coach has got to do that - having results like the Olympics shows they're able to.
"There is an expectation from the general public that they will have success, but that may not always be the case."
McLeod noted there had been a swing towards picking younger players, which may have an impact on players in their early 20s. "You certainly can't question the players' ability and, in almost all of the situations, they have been good enough, but there has to be questions asked when you've got players at 21 [Harrison] and 23 [Millington] saying 'I don't know'," said McLeod.
"There is a lot of pressure, Hockey New Zealand wants to continue to be ranked at third and that brings more pressure, so they will want their players to keep playing. There are quite a few younger ones around that 20 to 23 age group, and a lot of the Northland girls fall into that category."
Harrison, younger sister of striker Charlotte who made her international debut as a schoolgirl, has played 93 times for the Black Sticks since her debut in 2009. Black Sticks coach Mark Hager has communicated only by email with Harrison, who is taking a break in Europe, but will sit down with her when she returns to New Zealand to work out a pathway back into the Black Sticks.
However, Harrison has taken her demotion well. On her Facebook page, she said: "Just having a wee break to get hockey mad again! No need to tiptoe round people I'm happy with the decision. I'll be back!!!"
Eleven of the 16 players who represented New Zealand at this year's Olympics, including Gemma Flynn, Katie Glynn, Stacey Michelsen and Anita Punt, have all been renamed in the squad. The other five have made themselves unavailable for 2013. Samantha Harrison will be part of the Development Squad in 2013.
New Zealand women's 2013 squad: Bridget Blackwood, Sam Charlton, Michaela Curtis, Sophie Devine, Gemma Flynn, Krystal Forgesson, Sian Fremaux, Amelia Gibson, Katie Glynn, Ella Gunson, Charlotte Harrison, Pippa Hayward, Rose Keddell, Julia King, Olivia Merry, Stacey Michelsen, Emily Naylor, Anita Punt, Cassandra Reid, Aniwaka Roberts, Bianca Russell, Sally Rutherford, Kayla Sharland, Jenny Storey, Petrea Webster.
NZ women's squad to play India in a six-test series from December 8-15: Sam Charlton, Michaela Curtis, Gemma Flynn, Sian Fremaux, Amelia Gibson, Katie Glynn, Ella Gunson, Charlotte Harrison, Pippa Hayward, Rose Keddell, Julia King, Olivia Merry, Stacey Michelsen, Anita Punt, Cassandra Reid, Aniwaka Roberts, Sally Rutherford, Jenny Storey, Petrea Webster, Georgia Barnett.