All of the New Zealand and West Indies players in isolation in Christchurch have tested negative for the novel coronavirus and are due to be released as scheduled on Thursday, a day ahead of their opening Twenty20 match in Auckland.

About 20 players and support staff from both sides arrived in New Zealand after their commitments in the Indian Premier League and underwent a 14-day mandatory isolation period.

They were able to train in small groups after their first Covid-19 test and had three tests while in isolation.

New Zealand Cricket, who confirmed the negative tests, said the players were likely to be released from about 10 a.m. (2100 GMT) on Thursday before heading to Auckland for the first of three Twenty20 games.

New Zealand, however, were forced to make some late changes to their squad for the first test match, which immediately follows the Twenty20 games, with all-rounder Colin de Grandhomme and left-arm spinner Ajaz Patel ruled out through injury.

De Grandhomme has bone bruising in his right foot and been replaced by Daryl Mitchell, while Mitchell Santner has replaced Patel, who is slowly recovering from a torn calf muscle.

"The unavailability of Colin and Ajaz has obviously had a flow on effect to our T20 squad who are providing the replacement players for the test squad," New Zealand coach Gary Stead said in a statement.

"Mitch and Daryl will be available for the final T20 game, before linking up with the test squad on Tuesday where we will monitor them closely to ensure they're fit and fresh ahead of the first test on Thursday."

Santner, who is one of the players still in managed isolation, has also been elevated to the captaincy for the final Twenty20 game, with Tim Southee joining the test squad.

Southee, who took the captaincy in place of the rested Kane Williamson, had only been named for the first two games and Stead said Santner was the natural choice to lead the side.