Pérez played his first match as a professional on 24 May 2014, starting in a 1–0 home success against FC Barcelona B in the Segunda División.[3] He was definitely promoted to the main squad in August.[4]
On 6 September Pérez scored his first goal, netting his side's only in a 1–1 away draw against Albacete Balompié, through a last-minute header.[5] He scored a brace on the 20th, netting all goals in a 2–0 away win against CD Mirandés.[6]
On 11 November 2014 Pérez renewed his link with Sporting, until 2019.[7] He contributed with 37 appearances and seven goals during the season, as his side returned to La Liga after three years.
Pérez made his debut in the main category of Spanish football on 12 September 2015, starting and being booked in a 0–1 home loss against Valencia CF.[8] The following 31 August, he was loaned to AD Alcorcón in the second tier, for one year.[9]