[6] Earlier into the 2009–10 campaign he was called by manager Pep Guardiola to the Spanish Supercup and UEFA Super Cup games, respectively against Athletic Bilbao and FC Shakhtar Donetsk, but finally did not make the bench on either occasion.

On 20 November 2010, Fontàs started for the first time in the league with the first team, assisting Pedro with a 50-meter pass for the fourth goal, as Barcelona trounced UD Almería 8–0 away.

[8] He made his UEFA Champions League debut on 7 December, against FC Rubin Kazan: as the Blaugrana had already progressed to the knockout stage as group winners, he scored in the 2–0 home victory, converting a pass from fellow youth graduate Thiago Alcântara.

[9] On 16 March 2011, Fontàs was promoted to the senior team on a permanent basis after Eric Abidal was diagnosed with a tumour in his liver, thus becoming unavailable for the rest of the season.

[15][16] On 15 October 2012, Fontàs was loaned to RCD Mallorca until the end of the campaign, as backup to João Victor who suffered a severe knee injury.