Aguero had to quit professional football due to heart issues being detected after receiving chest pains in his final game for Barcelona against Alaves.
A heart arrhythmia was confirmed as the reason behind the pains he had experienced after undergoing cardiological tests.
Aguero only managed five appearances for Barcelona with a sole goal coming against rivals Real Madrid.
The 33-year-old also had a spell at Atletico Madrid in Spain but is most known for his time at Manchester City.
Aguero won five Premier League titles during his time at the Etihad and netted 260 goals from 390 games and is the highest-scoring non-English player in the league's history with 184 goals.
Footage on social media shows the star on a football pitch against River Plate fans and was seen wearing a Barcelona shirt.
Aguero - who worked under Pep Guardiola during his time at City - believes the Spaniard is key for the club to continue winning trophies.
"It'd be ideal to give the project continuity and build upon the groundwork. City's style is a trademark, and Pep has been key to making it happen," he told Stake.
"I think the team is making history. In the past 10 years, City has claimed six Premier League titles and that's major. Things are coming together very well across many levels, and when that happens, success is closer to hand.
"With the last four years in mind, it's clearly Manchester City and Liverpool is one of the great rivalries of our time.
"But context is important - many other teams had excellent campaigns. That's the beauty of the Premier League - it's highly competitive, which contributes to the spectacle."