Subsequently, he represented English clubs Arsenal and West Ham United in the Premier League, before rejoining Alavés where he had played as a youth.

In the 2010–11 season, Pérez contributed five games and one goal (in a 3–0 home win against Real Valladolid on 6 November 2010)[4] as Rayo returned to La Liga after eight years.

Pérez netted a hat-trick on 4 November 2012 in a 4–0 home victory over Kryvbas Kryvyi Rih, including a long-distance volley from a corner kick delivery.

[8] He scored his first competitive goal on 17 August, contributing to a 3–0 home defeat of Skoda Xanthi, and on 24 November he equalised in a 3–1 win over Aris in the Derby of Northern Greece.

[10] On 18 July 2014, Pérez returned to Spain and joined his newly promoted hometown side Deportivo de La Coruña in a one-year loan deal, with a buyout clause.

[17] On 23 July 2015, in his first competitive match upon his return to PAOK, against NK Lokomotiva in the second preliminary round of the UEFA Europa League, Pérez scored the opener after Róbert Mak's shot was saved, in an eventual 6–0 home rout.

[25] He made his competitive debut in the 2–1 Premier League home win over Southampton on 10 September, which coincided with both his birthday and that of teammate Laurent Koscielny, whom he assisted for his team's equaliser.

[26] On 20 September 2016, during an EFL Cup away match against Nottingham Forest, Pérez scored his first goals for the Gunners, grabbing a brace in an eventual 4–0 victory in the third round.

[41] He found the net for the seventh time on 9 November against Real Valladolid, becoming the first player in the history of the competition to score in seven consecutive matches with two different teams, as he had done it before with Deportivo.

[45] Pérez agreed to a return to Deportivo on 31 December 2022, with the deal being made effective at the opening of the January transfer window;[46] the player himself paid €493,000 in order to be released.

[49] On 12 May 2024, Pérez scored from a direct free kick in the 1–0 victory against second-placed Barcelona Atlètic, securing the club's return to Segunda División after four years.