He is the younger brother of former Wakefield Trinity and Hull Kingston Rovers head coach James Webster.
In 2014, he returned to the Wests Tigers as head coach of their NYC team, winning 16 games and reaching the finals.
[12] In 2020, Webster joined the Penrith Panthers as an assistant coach ahead of the 2021 NRL season, replacing Trent Barrett.
[15][16] Webster led to the Warriors to a top four finish, and the club's first home semifinal since 2007, during a highly successful first season in charge.
[17] On 27 September 2023, Webster received the Dally M Coach of the Year award, after taking the New Zealand Warriors to a preliminary final from 15th on the ladder in 2022.