In 2021, Pinillos joined UD Mutilvera; initially a member of the Juvenil squad, he played one match for the B-team in the Primera Autonómica, before making his first team debut on 6 February 2022, playing the last six minutes in a 2–0 Segunda División RFEF loss to former side Izarra.[3] In July, he joined the structure of Deportivo Alavés, being initially a member of the C-team in the regional leagues.
Pinillos also featured for the reserves shortly after arriving, but only became a regular starter for the side during the 2024–25 season. On 12 July 2025, while making the pre-season with the main squad, he renewed his contract until 2027.[4]