[1] He made his senior debut with the reserves on 12 April of the following year, coming on as a second-half substitute in a 1–3 Tercera División home loss against Atlético Madrid B.
[3] He made his first team debut on 17 February, as he replaced Foued Kadir in a 1–1 home draw against CD Tenerife in the Segunda División.
[4] On 16 August 2018, Martínez joined Segunda División B side UD San Sebastián de los Reyes on loan for a year.
[6] Martínez made his La Liga debut on 1 December 2019, replacing Nikola Vukčević late into a 0–4 away loss against Getafe CF.
[9] Upon returning, Martínez was permanently assigned in the main squad for the 2021–22 campaign, but was loaned to second division side SD Huesca on 14 January 2022.