Born in Peralta – Azkoien, Navarre, Gil joined Athletic Bilbao's youth setup in 2008, aged 13.

[3] Gil made his professional debut on 24 August 2015, starting in a 0–1 home loss against Girona FC.

[4] He scored his first professional goal on 4 April of the following year, netting his team's first in a 2–1 home win against Real Oviedo.

Gil made his first team debut on 25 October 2017, playing the full 90 minutes in a 1–1 Copa del Rey away draw against SD Formentera.

[1] A regular starter in his first season as his side returned to the second division, he was rarely used in his second and moved out on loan to CD Atlético Baleares on 21 January 2020.