To get around the possible embargo, Chelsea may sign Aguero in January and immediately loan him back to the La Liga club till the summer.

Carlo Ancelotti would ideally want the striker in place to cover for the expected absence in January of Didier Drogba and Salomon Kalou, who should be part of the Africa Cup of Nations.

Big spender: Aguero could earn £170,000-a-week

However, sources in Spain insist that Aguero neither wants or will be allowed to walk out of the Vicente Calderon in the middle of the season.

He would also be cup-tied for the Champions League.

Aguero, who has a £54m buy-out clause written into his contract, would be made the highest-paid player in the Barclays Premier League if he made the switch to Stamford Bridge.

Aguero’s pay demands mean he is likely to earn more than Manchester City’s Emmanuel Adebayor, who is believed to be on a £170,000-a-week deal at Eastlands.

Ancelotti has been tracking Aguero for some time but was understood to be put off initially by Atletico’s astronomical price tag.

The Italian coach was also concerned by the player’s lack of maturity, while at one stage Chelsea were also not prepared to meet his excessive wage demands.

However, after seeing Aguero score two stunning goals against Chelsea in the 2-2 draw away at Atletico in the Champions League earlier this month - and with the transfer ban lifted, if only temporarily - Chelsea owner Roman Abramovich has changed his stance.