Lock Barrett, who was one of the two starters retained in the squad as New Zealand beat Fiji 47-5, had the operation after he returned home, the team posted on X.
There was no timeline given for his recovery and the 30-year-old could miss the start of the Rugby Championship next month.
New Zealand begin their title defence with two home matches against Argentina on August 10 and August 17, before travelling to South Africa for two matches against the Springboks on August 31 and September 7.
--Reuters--