[4] He made his senior debut in the 2008–09 season, playing with UE Vilajuïga – also in his native region – in the Tercera División, on loan.

In the 2014–15 campaign he was promoted to the first team and given the #25 jersey, playing understudy to both Claudio Bravo and Marc-André ter Stegen.

[6][7] Masip made his competitive debut for the main squad on 16 December 2014, in an 8–1 home win over SD Huesca at the Camp Nou in the round of 32 of the Copa del Rey.

[12] Amidst interest from clubs including Sevilla FC and RC Celta de Vigo, Masip extended his contract in July 2019 to keep him at the Estadio José Zorrilla until 2022.

[14] He played roughly two thirds of league matches as the team were relegated, including when his teammate suffered from the same virus in March;[15] in 2021–22 he was second-choice until December.