Apiata is one of seven Poppy Ambassadors that include former soldier Melanie Childs, former soldier and widow Tina Grant, All Blacks coach Steven Hansen, film-maker Sir Peter Jackson, Naval reservist and singer Rebecca Nelson and mental health advocate Mike King.
For King, the theme of this year's Poppy Appeal, "Not all wounds bleed", is an acknowledgement that the issue of mental health and addiction is being taken increasingly seriously across the country.
"For it to now be okay to ask for help and talk about problems is a groundbreaking moment," said King.
"I know Willie [Apiata], I know he gets counselling and I know his wounds aren't bleeding but they are there and they will be there forever.
"We need to acknowledge that and we need to make it okay.
"So for me this appeal has meaning and this isn't going to just help the veterans, past, present and future, this is going to help all New Zealanders overcome that final hurdle."
This year's Poppy Day will take place on Friday April 20 to raise funds to support New Zealand's 41,000 veterans, returned servicemen and women and their families.
NZME is an official media partner of this year's Pin A Poppy campaign. Visit http://www.pinapoppy.co.nz/ to donate – including the option to get a $3 virtual poppy via text.