At a press conference held by Barca for him, the 33-year-old Aguero officially announced his retirement.
In Barca's match against Alaves on 30 October, Aguero was substituted for heart problems. After the game, Barca officially announced that Aguero was detected with arrhythmias and would be on a long-term truce, and finally Aguero heeded the advice of the medical team and chose to retire.
Aguero came from the Argentine independent team's youth training and joined Atletico in the summer of 2006. In his five years at Atletico, Aguero made a total of 175 appearances, scoring 100 goals and contributing 45 assists.
In the summer of 2011, Aguero moved to Manchester City, and in the following 10 years, he made 390 appearances for Manchester City, scoring 260 goals and contributing 73 assists, becoming the city's all-time top scorer and legend. The most famous moment was the final round of the 11/12 season, when the 93rd minute and 20 seconds were beaten to help City snatch the Premier League title from the hands of their city rivals Manchester United.
This summer, the 33-year-old Aguero joined Barca as a free agent, and this season he has made five appearances, scoring the only one goal from the "national derby" against Real Madrid.
In 2008, Aguero competed in the Beijing Olympic Games with Messi, Di Maria and others, and won the championship.
As Aguero's best friend, Messi later posted on social media to say goodbye to his best friend.