Atlético de Madrid are in the market for a left-back for the coming campaign. No official confirmation will be forthcoming just yet, but the Calderón suits have already got down to business for the 2015-16 season.

The background to this search is well known. Filipe Luís departed against the club's wishes, having rejected the offer of a new contract that would have significantly increased his wages. When Emiliano Insúa asked to move to Rayo on loan, this left the 'Rojiblancos' short on the left side of defence, so a double swoop was sealed for Guilherme Siqueira (for €10 million from Benfica) and Cristian Ansaldi (on loan from Zenit).

However, neither of the two summer recruits has fully convinced, so the club is back on the hunt. These are some of the options being considered:

Re-signing Luís

Though he started on Sunday against Hull, the Brazilian has been unable to hold down a first-team place at Stamford Bridge, having been kept out of the side by César Azpilicueta.

Porto's Alex Sandro

There are three reasons why the highly rated Porto full-back could be a decent bet. His age - he is only 23 - means he could fill the position for years. Furthermore, his contract is up in 2016 and the Portuguese club needs to raise funds, which is why 'Dragoes' president Pinto da Costa has agreed to sell Danilo to Real Madrid.

Monaco's Layvin Kurzawa

Kurzawa is the latest name doing the rounds. Atlético are known to have a good relationship with the Principality outfit, they sold Falcao to the Monégasques, and so a deal for the 22-year-old France international may not be too difficult to strike.