Adu-Adjei joined the
Bournemouth academy in March 2021, following spells with the
Brentford and
Fulham academies. He began to be integrated into the Bournemouth first-squad during the 2022–23 season and was an unused substitute in the clubs
Premier League fixtures on occasion. He also played on loan at
Poole Town from February 2023. He signed a first professional contract with Bournemouth in February 2023. He started the 2023–24 season playing for the Bournemouth U21 side in the
Premier League Cup, and the
Professional Development League. He made his professional debut playing for Bournemouth in the
FA Cup third round, on 6 January 2024, away against
Queens Park Rangers in a 3–2 win. On 5 June 2024, he signed a new long-term contract with Bournemouth. On 1 August 2024, Adu-Adjei joined
League Two side
Carlisle United on a season-long loan deal. He was recalled in January 2025. On 26 August 2025, Adu-Adjei joined
Croatian Football League side
Rijeka on a four-year deal. ==Career statistics==