Ejeheri joined Arsenal at the age of eight. In August 2021, Ejeheri signed his first professional contract with the club.[2][3]
On 6 July 2022, Ejeheri signed for National League South club Chelmsford City on loan until January 2023.[4] Over the course of Ejeheri's time at Chelmsford, Ejeheri made 25 appearances in all competitions, keeping 12 clean sheets.[5]
On 19 January 2023, Ejeheri signed for Finnish club SJK until the end of the English season.[6] On 28 January 2023, Ejeheri made his debut for SJK, playing the full 90 minutes in a 1–0 loss against KuPS in the Finnish League Cup.[7] On 8 July 2023, SJK announced Ejeheri would leave SJK after the expiry of his loan deal, with Ejeheri keeping nine clean sheets in 14 Veikkausliiga games during his time at the club.[8]
Ejeheri was released by Arsenal at the end of the 2023–24 season following the expiration of his contract.[9]