[1] Born in Bilbao, Biscay, Basque Country, Muñoz made his senior debut with JD Somorrostro in the regional leagues.
[2] Muñoz made his senior debut on 21 August 2016, starting in a 2–1 away loss against UD San Sebastián de los Reyes.
[3] On 30 March 2017, Muñoz agreed to a two-year contract with La Liga club Athletic Bilbao, which was made effective on 1 July; he was initially assigned to the reserves also in the third division.
[4] He played his first competitive match with the main squad on 25 October, coming on as a second-half substitute for Ager Aketxe in a 1–1 draw at SD Formentera in the round of 32 of the Copa del Rey.
[5][6] After helping CD Castellón[7] return to the Segunda División after ten years at the end of 2019–20, Muñoz made only one official appearance in the first part of the following season.