SERGIO AGUERO is set to announce his RETIREMENT next week, according to shock reports in Spain. Manchester City's all-time leading goal-scorer, still only 33, suffered breathing problems during Barcelona's clash with Alaves last month. Aguero was taken to hospital for tests before being ruled out of action for at least three months to undergo a period of observation. He was diagnosed with a cardiac arrhythmia. But reports in Spain are now sensationally claiming Aguero is going to hang up his boots in the coming days. Barcelona journalist and streamer Gerard Romero revealed the news, tweeting: "Kun Aguero retires. "Heart problems force him to leave football activity. "A press conference has been scheduled to announce his retirement next week." Many other major Spanish publications were quick to back up the news. Last week, reports in Spain revealed the heart problem could lead Aguero to becoming 'incompatible' with the professional game and may no long be 'at a level required by Barcelona'. Barcelona are yet to release any official comment on Aguero's current status. But last week Aguero - who joined Barca on a free transfer in July - admitted he was staying 'positive'. The Argentine claimed: "Given the rumours, I tell them that I am following the indications of the club's doctors, doing tests and treatment and seeing my progress within 90 days. "Always positive." Aguero won 15 trophies including five Premier League titles during his ten-year stint at Man City, scoring 260 goals in 390 games. He also played 101 times for his country - scoring 41 times - finally helping Argentina win the Copa America earlier this year.