MacDonald, who has 17 caps for New Zealand, said this was her first season back in the NHL, after having a baby last year.
"It is really good [to be back], I am really enjoying it. It is good to play top-level hockey again after a break," she said.
"It has been a bit more difficult with juggling the family but my husband, and my mum and dad have been really supportive."
The NHL competition is contested between all eight hockey regions in New Zealand including Midlands, Northland, North Harbour, Auckland, Central, Capital, Canterbury and Southern.
The Midlands women's team won the NHL title last year and Hepi said they had high expectations again this season.
"It is pretty high expectations for us as defending champions, some of the older players have already stepped up and put down some ground rules," she said.
Hepi said they were focussed on having a tight team dynamic in the lead-up to the NHL and playing well as a team.
MacDonald and Hepi have already shown their class this year, scoring the majority of Midlands goals in pre-season.
Mitai-Ngatai has represented the Midlands men's team for the past two seasons and said they had a strong team this year. He said they had even imported Australia's Tim Deavin, who was part of the Australian national team which won the hockey world cup earlier this year.
Mitai-Ngatai, Hepi and MacDonald are the only Rotorua-based players and played club hockey for the Rotorua Aces this year. Local players still have to pay expensive fees and cover travel costs despite representing their regions in the national competition.
They said they would like to be better supported and invited sponsors to get behind the team.
The Midlands men's and women's teams begin their NHL campaign against Central in Taranaki tomorrow before facing North Harbour in Hamilton on Sunday. The games in Hamilton start at 1pm (women) and 3pm (men) at the Gallagher Hockey Centre.
