San Emeterio first appeared in the Segunda División B on 10 May, again from the bench in a 1–1 away draw with Coruxo FC. On 24 August he played his first match as a professional, replacing Javi Soria in the 64th minute of a 1–0 loss at Girona FC in the Segunda División.[3]
San Emeterio contributed 35 appearances during the campaign, as his team suffered relegation. He scored his first senior goal on 4 October 2015, in a 2–0 victory at Sporting de Gijón B.[4]
Sevilla
On 16 August 2016, both San Emeterio and his brother moved to another reserve team, signing a three-year contract with Sevilla Atlético in the second division.[5] He netted three times from 39 games (all starts) in his second year, which ended in relegation after the last-place finish.[6]
Valladolid
On 16 August 2018, San Emeterio joined Real Valladolid on a three-year deal, being immediately loaned to Granada CF in the second tier.[7] He made his La Liga debut while at the service of the former club, starting the 1–1 away draw against Real Madrid on 24 August 2019.[8]
Cádiz
On 6 January 2022, San Emeterio was loaned to top-flight side Cádiz CF until June, with a buyout clause.[9] On 7 August, he agreed to a permanent four-year contract at the Nuevo Mirandilla.[10]