Club career
Allende started his youth career at Cobreloa. After Chile's participation in the U-17 World Cup, he caught the interest of Colo-Colo and Universidad de Chile for his signature, although neither move materialized.
In 2016, the player transferred to Deportes Santa Cruz of the Segunda División de Chile in order to gain more playing time, making his debut against Naval. In his second season at the team, he scored his first senior goal against Melipilla, and became a regular starter, finishing the campaign with four goals.
Allende had a two-month trial with English club Arsenal, featuring for their under-19 team at the Durban International Cup. The team won the competition, and the player was invited to further trials with the club. In April 2017, following a third trial, the English tabloid press reported that Arsenal had offered Allende a professional contract.
Necaxa
With this being so on 7 September 2017 Allende signed up with Mexican side Necaxa, with the intention of rejoining the club in 2018 while remaining on loan with Santa Cruz.
Mamelodi Sundowns
On 24 August 2022, Allende was announced as new player of South African club Mamelodi Sundowns in what was a record transfer fee of R51 million (€3 million) for a player in the South African Premiership and made his debut in the same day scoring a goal versus Stellebosch. He ended his maiden season with 19 appearances for the club scoring 2 goals and providing 2 assists to help them to the 2022–23 league title with his second goal being a much needed winner against Amazulu.
During the 2023–24 season, he continued to feature prominently in Sundowns’ possession‑based system under Rulani Mokwena. He recorded 2 goals and 3 assists in 18 league matches.
Allende enjoyed one of his productive creative campaigns in 2024–25, registering 2 goals and 4 assists in 24 league appearances as Sundowns secured another domestic title.He also featured in the African Football League, helping the club win the title.
In the 2025–26 season, Allende added 4 goals and 1 assist in 21 league matches, while continuing to play across multiple midfield and wide positions under Miguel Cardoso. His versatility, press resistance, and passing range made him a consistent starter as Sundowns won their second Champions League title.
International career
On 15 June 2015, Allende made his debut for Chile U-17 in a friendly defeat against Paraguay. He was later selected on the list of players that would take part in the tournament, held on home soil. He was a starter on Chile's four matches at the U-17 World Cup, netting against Nigeria and the United States.
On 16 October 2016, Allende made his debut for the Chile U-20 in a friendly win against Paraguay U-20 adding another cap against Ecuador U-20, but was ultimately left out of the final squad for the 2017 South American Youth Football Championship. He scored his first goal for the U20's on 10 August 2017, in a friendly win against Japan.
At under-20 level, Allende represented Chile in both the 2018 South American Games, winning the gold medal, and the 2019 South American Championship.
Allende made his debut for Chile national team on 11 December 2021 in a 1–0 win over El Salvador.
