[6] After sitting through four Segunda División B matches as an unused substitute, manager Xavi Calm gave him his league debut on 22 December 2018; he replaced Carlos Esteve in the 90th minute of a 3–1 win at home to Ebro.
[7] As part of the relationship between Cornellà and Birmingham City, Fernández trained with the English Championship club in January 2019[8] and again during the close season.
[9][10] He scored seven Professional Development League goals during the initial six months, making him joint top scorer (with Odin Bailey), and was rewarded with a new contract to run until the end of the 2019–20 season, with an option for the club to extend it for a further year.
[11] Before that season resumed after a three-month suspension due to the COVID-19 pandemic, the club took up their option to extend his contract and Fernández was given a first-team squad number.
[17][18] Birmingham confirmed that Fernández would leave the club when his contract expired at the end of the season,[19] and he returned to Spanish football with Huesca B of the Segunda División RFEF.