Pace bowler Hayley Jensen and batter Bella James (quadriceps) have been scratched from the three-game series, as has wicketkeeper-batter Izzy Gaze (hip flexor).
Otago wicketkeeper-batter Polly Inglis and left-arm seamer Bree Illing, who both made their international debuts during last week’s ODI series, will replace Gaze and Jensen for the T20 series.
Central Hinds all-rounder and former New Zealand A representative Flora Devonshire receives her maiden call-up, replacing James.
Inglis, like many Sparks enjoying an excellent summer, took five catches in the three-ODI series against Sri Lanka and had a high score of 34 not out.
Illing also made a promising debut with four wickets, twice dismissing Sri Lankan captain Chamari Athapaththu.
White Ferns coach Ben Sawyer said the injuries were unfortunate.
Regular keeper Gaze, who played as a batter only during the ODI series, sprained her left hip flexor when fielding during the third ODI. Her rehabilitation timelines are being reviewed.
Assessments have determined that Jensen’s and James’ injuries, which ruled them out of the ODI series, require further rehabilitation before returning to play.
"We’re all feeling for Izzy, Hayley and Bella," Sawyer said.
"It’s disappointing for the team and the players, but I know those three have the determination and resilience to bounce back."
Sawyer said Illing and Inglis had shown they were ready for international T20 cricket.
"Bree and Polly had a really positive start to their ODI career.
"They both showed great intent and execution and I’m confident they’re ready to take on this next challenge."
Devonshire was an exciting prospect, he said.
"Flora’s shown a lot of all-round potential at the domestic level and is another exciting young player that has qualities consistent with what we’re looking for in the White Ferns."
Both the second T20 international, also in in Christchurch, and the third, in Dunedin, are double-headers with the Black Caps, who host Pakistan. — APL
