Tejón scored his first senior goal on 5 February 2023, netting the B's winner in a 2–1 Segunda Federación away win over Lleida Esportiu.[3] On 10 August, after spending the pre-season with the main squad, he renewed his contract until 2026.[4]
Tejón made his first team – and La Liga – debut on 17 August 2024, replacing fellow youth graduate Jesús Vázquez late into a 2–1 home loss to FC Barcelona.[5][6]