Career
Born in Zaragoza, Aragon, Martínez joined Atlético Madrid's youth categories in May 2020, from hometown side Real Zaragoza. He was promoted to the reserves ahead of the 2023–24 season in Primera Federación, and made his senior debut on 26 August 2023, coming on as a late substitute in a 2–0 home win over Antequera CF.
On 12 July 2024, Martínez renewed his contract with Atleti until 2027. He subsequently established himself as a regular starter for the B-team, and made his professional – and La Liga – debut with the main squad on 11 April 2026, starting in a 2–1 away loss to Sevilla.
On 1 September 2026, Martínez was definitely promoted to the first team.
