Racing Born in Sierra de Ibio,
Mazcuerras,
Cantabria, San Emeterio joined
Racing de Santander's youth academy in 2007, aged 10. On 14 January 2014, before even having appeared with
the reserves, he made his senior debut, coming on as a late
substitute in a 2–0 away win against
UD Almería for
that season's
Copa del Rey. 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. 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.
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. He netted three times from 39 games (all starts) in his
second year, which ended in relegation after the last-place finish.
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. 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.
Cádiz On 6 January 2022, San Emeterio was loaned to top-flight side
Cádiz CF until June, with a
buyout clause. On 7 August, he agreed to a permanent four-year contract at the
Nuevo Mirandilla. San Emeterio all but missed the
2023–24 season, due to recurrent knee injuries. On 6 August 2025, he left by mutual consent. ==Personal life==