In July 2020, Zarraga was called up to the pre-season with the main squad.[4] He made his professional – and La Liga – debut on 18 October, replacing Unai López in a 2–0 home win against Levante UD.[5][6] In February 2021 he signed a new contract running to summer 2023, also confirming his status as a first team squad member.[7]
Udinese
On 29 June 2023, Zarraga moved abroad for the first time in his career, signing a four-year contract with Serie A side Udinese Calcio.[8]