Born in Coristanco, Galicia, Rubén moved to FC Barcelona’s youth ranks in 1997, and reached the club’s reserves five years later. As Turkey’s Rüştü Reçber went on loan in the 2004–05 season he was handed the role of third-choice in the first team, behind Víctor Valdés and Albert Jorquera.

On 18 December 2004, Rubén entered the pitch for Xavi after Valdés’ dismissal in a 1–1 away draw against Valencia CF, and kept his place for the subsequent 2–1 La Liga win over Levante UD. After some more years in the B-squad and an unassuming second division loan at Racing de Ferrol (no games played, eventual relegation), he was released by Barcelona, joining FC Cartagena in the third level and going on to play in more than 80 official matches in his first two seasons combined, promoting in the first and nearly repeating the feat in the second.

On 25 August 2010, Rubén was sold to Málaga CF for €1.35 million. He made his official debut on 23 September, keeping a clean sheet in a 2–0 win at Getafe CF. However, in late December, he fractured his right wrist in training – his second major physical ailment whilst at the club – being sidelined for the rest of the campaign and prompting the Andalusians to sign another goalkeeper in the winter transfer window, as Sergio Asenjo also suffered a severe injury (knee).

After a series of bad performances upon his recovery and also due to the managerial change at Málaga, Rubén lost his position to Willy Caballero, being further demoted to third-choice after the club signed Carlos Kameni in January 2012. He was loaned to fellow league side Rayo Vallecano for the 2012–13 season.

On 23 July 2013, Rubén returned to the Madrid club on a permanent deal, signing a one-year contract. On 28 May of the following year, he moved to fellow league team UD Almería in a one-year deal.

On 2 June 2015, after suffering relegation with the Andalusians, Rubén agreed to a three-year contract with Levante UD. After again dropping down a level, he joined Deportivo de La Coruña after cutting ties with the former.

On 5 July 2018, Rubén joined CA Osasuna in the second division.