The duo picked up adductor strain injuries in last month’s series against England.
They will be on managed workloads for the three-test series against the New Zealand men, which begins on Sunday in Wellington.
Games follow on both Monday and Tuesday.
Crampton returns to captain the 16-player squad although she will be without her vice-captain, as injured defender Sulu Fitzpatrick remains in Auckland.
Young defenders Georgia Tong and Paris Lokotui have been retained for the series.
Heffernan was included in the matchday squad for the second test against England, but did not take the court and is yet to debut.
Northern Mystics shooter Jamie Hume, who is from Clyde, also retains her spot.
Silver Ferns coach Dame Noeline Taurua said
she was looking forward to making further progress following last month’s series against England.
‘‘This is a unique series for us, with Aotearoa men bringing something different to the court.
‘‘There were areas where we definitely saw improvement over the three tests with England, but it’s important that we also focus on the parts of the game that we couldn’t sustain against the Roses.
‘‘Playing matches on three consecutive nights is another opportunity to test our athletes in an environment that is similar to what we will face at next year’s Commonwealth Games.
‘‘We need to ensure we make the most of our time on court against a quality opposition as we look further ahead to next year and beyond.’’