New Zealand Cricket offers contracts to the top 20 players in the country, indicating those players considered most likely to make up Test and one-day teams in the year starting from June.

Opening batsman Craig Cumming and James Marshall, who both played in New Zealand's home Test series loss to Australia in March and the victory over Sri Lanka in April, were both offered contracts in place of Butler and Sinclair.

Cumming made a solid start to his Test career scoring 74 against Australia in March. Marshall, twin-brother of fellow top-order batsman Hamish, made his Test and one-day debut against Australia earlier this year.

Butler is considered the second fastest bowler in New Zealand behind Shane Bond who is recovering from a series of lower-back stress fractures.

However, Butler has struggled with a back injury and received limited playing time during the season.