*Undated
Barcelona striker Sergio Aguero has announced his retirement from football at the age of 33 due to a heart condition.
Aguero has not played since the end of October when he was taken off during the first half of Barca's draw with Alaves after experiencing chest pain.
Barcelona later announced that the discomfort had been caused by an arrhythmia - a broad term to describe any heart rhythm that is not completely normal - which would require treatment over a three-month period.
The former Manchester City forward has since been subjected to regular cardiac exams to monitor his health, with the results advising him it would be a risk to carry on with his professional career.
He announced his retirement at a news conference on Wednesday December 15th, joined by Barca president Joan Laporta.
An emotional Aguero said: "This conference is to announce I have decided to stop playing professional football. It is a very difficult moment. The decision I have taken for my health; the problem I had a month and a half ago. I have been in good hands with the medical staff. I made the decision 10 days ago after doing everything possible to have some hope of playing on. I am very proud for my career. I have always dreamed of a professional career since the first time I touched a ball at five."
"I want to thank Atletico Madrid who took a chance on me when I was 18 and Manchester City, everyone knows who I feel about City and how well they treated me there."
Barca legend and City manager Pep Guardiola was in attendance at Camp Nou alongside director of football Txiki Begiristain. The entire Barca first team squad and representatives from Aguero's former clubs were also present.
"Sergio I think, as we just saw, we are left with deep joy and excitement with what you could have been here at Barcelona, but anything you need with your condition we are here at your disposal," Laporta said. "You will be remembered not just as a player, but as a friend. A new journey awaits and I am sure it will be just as successful. You deserve it."
City also paid tribute to Aguero on social media and posted: "King Kun. Everyone at Manchester City would like to take this opportunity to thank @aguerosergiokun for his incredible contribution to our success over the last decade and wish him well in his retirement."
Aguero joined Barca on a free transfer in the summer from City. A calf injury delayed his debut until October, with his first goal coming in the Clasico defeat to Real Madrid.
Madrid also paid tribute to Aguero online and posted: "It was an honour to compete against a player like you, one of the best players in the world. Good luck to you and your family." Aguero was making just his fifth appearance - and only his second start - for his new club in the Alaves game on October 30th when he experienced breathing problems.
Aguero burst onto the scene in Argentina as a teenager with Independiente before signing for Atletico Madrid in 2006. He scored 102 goals in five years in Spain before joining City in a deal worth around €40 million.
In Manchester, Aguero scored the dramatic last-minute winner against Queens Park Rangers on the final day of the 2011-12 season to help City win their first Premier League title. In total, he won 15 trophies in England, including five league titles, and is City's record goalscorer with 260 goals in 390 appearances. Aguero has also won 101 caps for Argentina, scoring 41 goals, and was part of the squad that won the Copa America last summer and was a runner-up at the World Cup in 2014.