In July 2012, Capa was promoted to the first team after appearing once with the main squad in 2011–12.[5] In the following campaign, he played 24 matches and scored five goals (adding six games and two goals in the playoffs) as the Armeros returned to Segunda División after a four-year absence.[6]
Capa played his first professional match on 18 August 2013, starting in a 2–1 away win against Real Jaén.[7] He scored his first goal on 28 September, but in a 3–2 loss at Sporting de Gijón.[8] He appeared in a further 30 games while netting once[9] during the season, being promoted to La Liga for the first time ever.[10]
Capa made his debut in the top flight on 24 August 2014, starting in a 1–0 home victory over Real Sociedad.[11] He scored his first goal in the competition on 8 December, his side's last in a 5–2 home rout of UD Almería.[12]
During the 2015 pre-season, Capa was converted from a winger into a right-back by new manager José Luis Mendilibar.[13] On 19 November of that year, with the club still in the top tier and him as an undisputed starter, he renewed his contract until 2018.[14]
Athletic Bilbao
On 1 September 2017, Capa agreed to join former youth club Athletic Bilbao[15] for four years, with the deal being made effective in July 2018.[16]Dani García made the same move; within weeks they were joined by another former teammate Yuri Berchiche, and before the end of the calendar year by the coach from their Eibar promotion seasons, Gaizka Garitano.[17] He scored his first goal for Athletic on 10 November 2019, netting the 2–1 winner in the final minutes of the home fixture against Levante UD through a volley from outside the box; he also provided the assist for the equaliser by Iker Muniain in the same game.[18]
Having previously been a regular starter, Capa made only one competitive appearance in the 2021–22 campaign under head coach Marcelino García Toral, and that consisted of just a few minutes as a late substitute. Subsequently, he was highly critical of the manager,[19] and with no agreement reached on a new contract – even after negotiations resumed when Jon Uriarte was elected as the new president and Ernesto Valverde was brought as the new coach – he appeared set to leave the club.[20] However, eventually a new deal was reached in July 2022, with the player staying at San Mamés for at least one more season and potentially a second if targets were met.[21][22]
Levante
On 15 August 2023, Capa signed a one-year contract with Levante UD in the second division.[23]
^Boudet, François Miguel (26 January 2018). "Éibar: Ander Capa, gros plan sur la comète" [Eibar: Ander Capa, big plan under the comet] (in French). Furia Liga. Retrieved 7 June 2023.
^Río, Endika (2 July 2022). "Capa no renueva y dice agur al Athletic" [Capa does not renew and says agur to Athletic]. Mundo Deportivo (in Spanish). Retrieved 12 August 2022.