Mills ruled out of third Test
Southee made his international debut in the Twenty20 matches against England last month, where he impressed with his pace and control. He then joined the New Zealand Under-19 World Cup squad, taking 17 wickets at 6.64 to emerge as the Man of the Tournament.
"He is a really good talent and he does swing the ball a bit," said Andrew Strauss, who played alongside Southee at Northern Districts earlier this year. "He'll be pretty excited to make his debut."
Even so, the loss of Mills will be a blow for New Zealand, especially after his performance in the first Test when he ripped through England's second innings with four quick wickets. "It's something I haven't had before," he said of his injury. "I've had strains and tears before and I know what they feel like. This is just the back of the knee.
"It all started in the Twenty20 game back at Eden Park," said Mills. "It's sand-based and I dove into it and got jammed up, really. Ever since then it has been niggling me. It's just been hard to run freely. Not only in the bowling but in the outfield as well."
Mills admitted that the strain of back-to-back five-day Tests had taken their toll. "After the heavy workload in the first three days of the last Test, it got tired there towards the end. It came up with a little tear in the top of my calf muscle. I don't have an issue with my calf muscle at all. It feels fine. It's just the inflammation around that tear that is giving me some problems."
Even though he will take no part in the decider at Napier, Mills will look back on the series with fond memories, and already has his sights trained on the tour of England in May. "At the start of the summer we were always considered the better one-day side and they were always the better Test side," he said. "To win that first Test was huge for us and we probably only lost one session in the second Test when Ambrose got away from us.
"I definitely feel we are competing with them," he added. "I personally consider this as part of a six-Test series and whoever wins this Test match will get some momentum going into the Test series in England."