Troup made his Test debut for the New Zealand national team on 18 November 1976 against India.

In 1979/80, at the dramatic conclusion to the First Test against Clive Lloyd's West Indians at Carisbrook, Dunedin, Troup was joined at the crease by Stephen Boock with New Zealand 9/100 and needing four more runs to win this historic match.

In a controversial tour, marred by umpiring disputes and some ugly onfield behaviour by the tourists, New Zealand won the series 1–0 after drawing the next two tests in Christchurch and Auckland.

[1] In the 2010 Auckland Council elections Troup ran in the Manukau Ward, placing fifth with 9,136 votes.

[2] In the 2016 Queen's Birthday Honours, Troup was appointed an Officer of the New Zealand Order of Merit for services to sport and the community.