O’Rourke is set to be out of action for at least three months after scans revealed the fast bowler has a stress fracture in his lower back.
The 24-year-old sustained the injury while bowling in the first test against Zimbabwe earlier this month.
That means O’Rourke will not be available for the Black Caps opening white-ball tours of the home summer against Australia, England and the West Indies.
Phillips (groin) missed the Zimbabwe tour and will be reassessed in a month’s time, while Allen is set for three months on the sideline after undergoing surgery on his right foot.
White-ball captain Santner returned home from The Hundred during the weekend after experiencing groin pain.
He is set to have abdominal surgery and will be out for about a month. His participation in the Australian T20 series hinges on a rapid recovery.
Black Caps coach Rob Walter said he felt for O’Rourke.
“He’s had such an impressive start to his career and so naturally it is disappointing when an injury like this comes along, but he’s a resilient guy and determined to put the work in and come back stronger,’’ Walter said in a press release.
Walter said Santner would be provided every opportunity to play in the series.
“Mitch is a world-class player and a crucial part of our T20 side from a skills and leadership point of view.
“With that in mind, we expect to name him in our squad when we announce it in a couple of weeks' time, and from there we can assess how his rest and rehabilitation progresses following surgery, before making a call on the eve of the series.
“It’s disappointing to lose the services of Glenn and Finn, who have played important batting roles in our T20 set up in recent times.
“Like in Zimbabwe, their unavailability will present opportunities for others to put their hands up in what’s going to be a hugely exciting and important series against Australia.”
There is some good news on the injury front. Wellington paceman Ben Sears has recovered from the side strain that saw him miss the tour of Zimbabwe and is expected to be available for the start of the home summer.
— Allied Media
