Born in Maipú, Mendoza, Pérez began his career in Deportivo Maipú, like his father, and started his professional playing career with Godoy Cruz, where he wrote his name into club history by scoring a fifth-minute goal in the 1–1 draw with Belgrano on 9 September 2006. This was the first goal ever scored by Godoy Cruz in the Argentine first division. In total, he scored 12 goals in his career at Godoy Cruz, most coming from penalties. In 2007, Pérez joined Estudiantes de La Plata, where he finished as runner-up with the team in the 2008 Copa Sudamericana. He was then a first team regular in the team that won the 2009 Copa Libertadores.
Benfica
On 8 June 2011, Pérez signed a five-year contract with Portuguese club Benfica for a fee rumored to be around €5.5 million for his full rights from Estudiantes.[4] After a serious knee injury sustained in the Champions League qualifiers, Pérez was loaned back to Estudiantes for six months on 9 February 2012.[5]
On 27 July 2012, at the Eusébio Cup, Pérez scored a long-range goal against Real Madrid from a tight angle to complete a 5–2 win.[6]
In the 2013–14 season, his influence was further increased after the departure of Matić to Chelsea on 15 January 2014, becoming a vital piece in Benfica's domestic treble (Primeira Liga, Taça de Portugal and Taça da Liga) and their second consecutive Europa League Final. Pérez, however, was not present in the eventual loss on penalties (4–2) to Sevilla in the final, having picked up a suspension in the semi-final against Juventus on 1 May 2014.[8][9] His performances attracted attention from other clubs,[10] while Benfica manager Jorge Jesus named Pérez his side's most difficult player to replace and the "brain" of the team.[11][12] On 6 July 2014, Pérez won the Player of the Year award.[13]
On 2 January 2015, Spanish La Liga club Valencia CF signed Pérez[14][15] for a transfer fee of €25 million,[16] the tenth-highest ever fee for an Argentine player.[17] On 4 January, he debuted for Valencia in a home win over Real Madrid (2–1) in La Liga.[18]
River Plate
On 29 June 2017, Pérez returned to Argentina and signed for River Plate.[19]
Ahead of a Copa Libertadores match on 19 May 2021, River Plate announced that over twenty players, including all four rostered goalkeepers, would miss the match due to a COVID-19 outbreak within the squad. With no substitutes, the injured Pérez volunteered to play in goal for the entirety of the match against Colombian side Independiente Santa Fe in which River Plate won 2–1.[20] Pérez made a number of key saves and was awarded with the man of the match for his performance.[21][22] On 21 April 2021, Pérez extended his contract until December 2023.[23]
Return to Estudiantes
In January 2024, Pérez returned to Estudiantes for a third spell, signing a one-year contract.[24]
On 2 June 2014, Pérez was called up for the 2014 FIFA World Cup by manager Alejandro Sabella.[27] After midfielder Ángel Di María sustained an injury in the quarter-finals, Pérez started in his place in both the semi-final and final against Germany, which Argentina lost 1–0 after extra time.[28][29]
In May 2018, Pérez was named in Argentina's preliminary squad for the 2018 FIFA World Cup,[30] but did not make the final list.[31] However, on 9 June 2018, he was called up as a replacement for the injured Manuel Lanzini.[32]
^"Comunicado" [Announcement] (PDF). S.L. Benfica (in Portuguese). CMVM. 2 January 2015. Archived from the original(PDF) on 3 January 2015. Retrieved 3 January 2015.
^"Comunicado" [Announcement] (PDF). S.L. Benfica (in Portuguese). CMVM. 29 December 2014. Archived from the original(PDF) on 29 December 2014. Retrieved 29 December 2014.