Seb was a key part of the Under-18s squad in 2024/25, which found success in both the Youth Alliance League South and the FA Youth Cup, reaching the quarter-finals. The midfielder’s energy and versatility were on show, scoring goals and providing assists in many competitions at the under-16s and -18s levels. He is a former student of Coombeshead Academy, who also played for Saints Southwest. Seb is a first-year apprentice for 2025/26.

On 23 September, 2025, Seb scored on his first-team debut, after coming on as a substitute in a 6-2 Vertu Trophy win over Spurs Under-21s. At 16 years and 279 days, this made him the youngest scorer in Argyle's history.

On 19 March, 2026, Seb signed his first professional contract with Argyle, nine days after making his first league appearance, against Wigan Athletic.