Both were part of the sides that claimed Commonwealth Games silver in 2010 and bronze in 2014, and fell agonisingly short of a maiden Olympics final in 2012 after losing a penalty shootout in the semifinals.
"I was very excited and shocked at the same time to receive the honour. It's a real privilege and obviously great for hockey," Whitelock said.
Whitelock played four Olympics, three Commonwealth Games and two World Cups, and listed the 2012 Olympic campaign as a career high.
"For the first time making the semifinals, it was a massive highlight. Playing the Dutch in the semifinal was huge. It was on the world stage and other teams around the world started to take notice of the Black Sticks."
After retiring in 2016, Whitelock announced last November an international comeback, targeting the 2020 Tokyo Olympics. With the Olympics delayed a year due to Covid-19, it remains 'wait and see' whether she'll make a fifth Olympics.
"I'm just trying to keep fit over this time. Hockey is starting up again. It's been good to get back home with the family and be settled a bit. We'll have to wait and see for what goes ahead with Tokyo next year," Whitelock said.
Gaddum, who became New Zealand's most capped player in 2014, said she couldn't believe she had been named on the honours list.
"I feel extremely honoured to be recognised for my service to hockey and receive this special award," she said. "Hockey has been a huge part of my life since I was a young girl, and being involved with Hockey
New Zealand and the Black Sticks for 12 years was a really special time in my life."
The 34-year-old continues to play and coach at club level in Hawke's Bay and helped establish a new hockey club in Havelock North in 2018.
