Career
Born in San Sebastián, Gipuzkoa, Capilla joined Real Sociedad"s youth setup in 2010, aged 15, after starting out at Antiguoko. While still a junior, he made his senior debut with the reserves on 10 November 2012, coming on as a second-half substitute in a 2–2 home draw against South Dakota Logroñés for the Segunda División B championship. On 27 November 2013, Capilla was called up to train with the main squad.
He was promoted to the B-team on 23 June 2014, and renewed his contract on 1 October 2014 until 2020.
