Pablo Aimar

River Plate

Aimar's football career begun in earnest when he was offered the chance to play for Estudiantes de Río Cuarto by youth coach Alfie Mercado. He trained with the club's academy three times a week and it was there that he was spotted by River Plate who offered the chance to join their own academy. Aimar's father initially prevented him from joining River as he felt he was too young to be playing football, but relented after manager Daniel Passarella personally asked him to allow his son to play. Having turned down the opportunity to attend medical school to pursue a career in football, Aimar made his debut for River on 11 August 1996 against Colón. His first goal for the club came on 20 February 1998 against Rosario Central. Aimar lifted six titles with River between 1996 and 2000, scoring 21 goals and recording 28 assists in 82 league appearances for the club, with his final appearance coming on 17 December 2000 in a 3–2 loss to Lanús.

Valencia

In January 2001, Spanish La Liga side Valencia signed Aimar from River for a club-record fee of €24 million (£13 million). He made his debut for the club the following month against Manchester United and drew praise from three-time Ballon d'Or winner Johan Cruyff for his performance after the match. The following weekend he scored on his La Liga debut, netting in a 2–0 away win over Las Palmas. Aimar immediately became a key figure in Valencia's midfield under Héctor Cúper and helped the club reach the 2001…

Aimar first represented Argentina at youth levels. Along with future senior team players Esteban Cambiasso and Juan Román Riquelme he won the 1997 FIFA World Youth Championship and went on to earn 52 senior caps following his debut in 1999, scoring eight international goals in total. He represented Argentina at the 1999 and 2007 editions of the Copa América, at the 2002 and 2006 FIFA World Cups, and at the 2005 FIFA Confederations Cup. In the 2002 World Cup, for which he was picked ahead of Riquelme, Aimar appeared against England, subbing in for Juan Sebastián Verón in the 1–0 loss, which led coach Marcelo Bielsa to start him against Sweden at the latter's expense. Aimar scored the last goal of the 2005 FIFA Confederations Cup during Argentina's 4–1 loss in the final to champions Brazil. He also appeared with the national side in the 2007 Copa América, scoring a goal in a 4–1 win against the United States in his team's opening group match of the competition; Argentina went on to reach the final of the tournament, losing out to Brazil once again, this time 0–3, with Aimar coming on as a second-half substitute for Cambiasso. After several months in the sidelines, Aimar received another international callup in October 2009, for decisive 2010 World Cup qualifiers against Peru and Uruguay. In the match against the former he repaid the faith placed in him by coach Diego Maradona, assisting Gonzalo Higuaín for Argentina's opener with a through ball, in an eventual 2–1 win.

An technical and creative attacking midfielder with a small frame, Aimar was a right-footed player with a vast array of skills and scoring abilities. He excelled in a free role as an advanced playmaker where he was able to utilize his dribbling skills, vision and passing ability to create chances for teammates and orchestrate attacks. Moreover, he was a free kick specialist. His skills and playing style earned him comparisons with Diego Maradona in his youth. He was given the nicknames El Payaso (the clown) and El Mago (the wizard) throughout his career. Compatriot Lionel Messi stated in 2002 that Aimar was one of his biggest influences as a player. In addition to his playing ability, Aimar also drew praise for his leadership qualities.

Aimar was appointed as coach of the Argentina national under-17 football team in July 2017. His under-17 team won the South American U-17 Championship in 2019. In 2022, Aimar was appointed as an assistant coach at the Argentina national football team. He was part of the Argentina managerial team who won the 2022 FIFA World Cup. He was also part of the managerial team at the 2026 World Cup.