All Whites and West Ham defender Winston Reid will miss the start of the English Premier League season due to injury.
The 30-year-old will have surgery on a knee injured last season and has been ruled out for three months.
He suffered the injury in March during a 4-1 defeat to Swansea City, when his foot stuck in the ground and forcefully twisted his knee.
The Hammers will also be without former England international Andy Carroll, who has had an operation on his ankle and will also miss three months.
"Winston has been suffering some swelling around the knee injury that he sustained at Swansea last season and he too is in need of explorative surgery to clean up the area," said Richard Collinge, head of the club's medical department.
"We have decided that this is the best course of action to ensure that both players have a chance of returning to full fitness as soon as possible.''
New manager Manuel Pellegrini has aired his disappointment at losing two key players.
"We are obviously unfortunate to hear that Andy and Winston have suffered setbacks," he said. "This is a big blow for them and us, but we hope to see them back in action as soon as possible.
"It does mean that we have lost two players in key areas though and we’ll continue to work hard with the owners to make further additions to strengthen the playing squad, beyond the five new signings already confirmed."
Reid has made 222 appearances for the club since joining in 2010.
West Ham opens their 2018/19 season against Liverpool on August 13 (NZ time).