[2] Imanol was promoted to the reserves in Segunda División B ahead of the 2019–20 season, and immediately became a regular starter for the side.

He renewed his contract with the Lions until 2025 on 5 March 2021,[3] and moved to Segunda División side CD Mirandés on a one-year loan deal on 1 July, along with Iñigo Vicente.

[5] He scored his first professional goal seven days later, netting his team's second in a 2–0 home win over SD Amorebieta.

[7] Back to Athletic in July 2023, Imanol was definitely assigned to the first team during the pre-season,[8] and made his La Liga debut for the club as a second-half substitute on the opening matchday of the 2023–24 season, a 2–0 loss to Real Madrid at San Mamés.

[9] On 16 July 2024, Imanol joined Czech First League club Sparta Prague for an undisclosed fee.