[5] On 2 November 2021, he scored on his senior debut for Linfield in the Northern Ireland Football League Cup in a 11–0 win over PSNI.
[6] 28 days later, Marshall made his NIFL Premiership debut for Linfield, coming on as a 90th-minute substitute for Christy Manzinga in a 2–0 win over Carrick Rangers.
[10] Marshall was a member of the team which won the 2023 FA Youth Cup defeating Arsenal 5–1 at the Emirates Stadium in April 2023.
[11] On 16 January 2024, Marshall made his senior debut for West Ham, coming on as an 80th-minute substitute in a 1–0 FA Cup defeat against Bristol City.
[13] He made his West Bromwich debut on 3 February coming on as a 62nd minute substitute for Brandon Thomas-Asante in a 1–0 win against Birmingham City.