Barcelona striker Sergio Aguero 'tells close friends he will RETIRE from football... with the ex-Manchester City star set to bring his glittering career to an end' after cardiac arrhythmia diagnosis Sergio Aguero has told close friends he will bring his glittering career to an end after suffering heart problems, according to reports. The Barcelona striker was diagnosed with cardiac arrhythmia last month after being forced off with chest pains in their 1-1 draw against Alaves. The Catalan giants ruled the 33-year-old Argentine out of action for the three months as a period of rest once extensive medical tests had been carried out.