[citation needed] Boss retired from professional rugby after the 2016 Pro14 season with Leinster, returning home to New Zealand.

Boss played in New Zealand for the Hautapu Rugby Club in Cambridge and for the Waikato in the National Provincial Championship.

Boss's Irish ancestry meant that he was qualified to play rugby for Ireland through his maternal grandmother who was from Glenarm County Antrim.

He made three substitute appearances for Ireland on the 2006 Southern Hemisphere Tour and started against Australia in the Autumn internationals.

During one of his most memorable performances, Isaac scored an historic try against England in the famous Croke Park victory in February 2007.

Boss made just one appearance in the tournament, with Conor Murray and Eoin Reddan as Ireland’s first-choice scrum-halves.

[2] On 31 January 2020, it was announced that Boss would be appointed Head Coach of the King Country Rams in the Mitre 10 Heartland Championship for a two-year term.