According to the Spanish radio station, Atletico Madrid have got in direct contact with Aguero, who used to play for the Spanish side before he moved to Manchester City.
'Radio MARCA' also state that both the club and the player have demonstrated interest in a reunion. They report that Diego Simeone's side are planning a bid to bring the Argentine to the Wanda Metropolitano.
Atleti are in the market for a new forward due to the rumoured departure of Antoine Griezmann, whose links to Barcelona are growing stronger by the day. The Frenchman is Simeone's main threat going forward, and if he goes they will have to replace the goals that leave with him.
Aguero himself is reportedly not averse to the move, potentially due to the arrival of Gabriel Jesus at Manchester City, which has knocked 'Kun' of his perch as top dog in the striking ranks.
The forward left Atletico in 2011, having spent five seasons there, scoring 74 goals. He has established himself as a world class striker at City, and the English side will not be keen to let him leave. He is currently under contract until 2020.