Isaak joined the club at the age of seven and made his competitive First Team debut against Middlesbrough in October 2021. 

His first senior goal came in the Emirates FA Cup against Preston North End in January 2022.

The Wales U21 international spent the 2023/24 season on loan with KV Kortrijk in Belgium before returning to the Bluebirds setup in the summer of 2024.

Isaak netted two goals in nine league appearances in the 2024/25 season.