He made his Durham T20 Blast debut on 7 June 2024, against Leicestershire.
[2][3] Mustard was announced as having joined the Durham County Cricket Club academy in late 2021, ahead of the 2022 season.
Mustard has represented the England national under-19 cricket team, making debut against India U19 in November 2023.
[7] He retained his place in the England U19 team for their summer 2024 series against Sri Lanka U19.
[8] He is the son of former England international wicket keeper Phil Mustard.