Diego Simeone coy on Atletico Madrid attempts to secure return of Chelsea outcast Diego Costa

Atletico Madrid manager Diego Simeone is remaining tight-lipped on Los Colchoneros' attempts to secure a return to La Liga for Diego Costa, who is desperately seeking to leave Chelsea before the transfer window closes at the end of August.

Costa has been told in no uncertain terms that he does not feature in Antonio Conte's plans for the new Premier League season, a decision that was initially made seven months ago before being reinforced in a text message sent by the manager earlier this summer.

Despite seeing a ban on registering new players until the New Year upheld by the Court of Arbitration for Sport (Cas), Atletico were still said to be working hard to seal the return of Costa.

They could opt to sign the fiery striker and not play him or loan him out until January, or otherwise convince Chelsea to offload him elsewhere temporarily until they can officially register him in 2018.

"I don't want to comment too much," Simeone told reporters when quizzed on the Costa saga following a 3-2 friendly victory over newly-promoted Premier League outfit Brighton & Hove Albion at the Amex Stadium on Sunday (6 August).

"The fact is he is still with Chelsea. The most important thing to me is the work of my club in general, not only in training. I have to work with what I have.

"When I found there was no other possibility to get new players at the club I accepted it. Maybe I could improve the quality, but for the moment with this team I can work very well and I'm satisfied with that."

Transfer request

£50m-rated ($65m) Costa, who has now been replaced as Conte's first-choice forward by compatriot Alvaro Morata, was unsurprisingly left out of Chelsea's squad for their pre-season tour of the Far East and played no part in the subsequent Community Shield defeat to Arsenal at Wembley. The player's lawyer, Ricardo Cardoso, confirmed last week that his client's camp would submit a formal transfer request and "use all possible legal mechanisms to hold Chelsea responsible for their behaviour".

In an attack on the defending top-flight champions, Cardoso, who labelled Conte's "inadmissible and inexcusable" treatment of Costa as unfair and betraying a lack of respect, said it was now "impossible" for the 28-year-old to return to Stamford Bridge. A Chelsea spokesman later rubbished such strong criticism by insisting that both Costa and agent Jorge Mendes were aware of the original decision made back in January.

Despite Cardoso claiming that Costa only wants to play for Atletico, AC Milan have also been heavily linked with the Spanish international over recent weeks. Sporting director Marco Fassone admitted that the club did hold talks with Mendes in July, although there have been conflicting reports as to whether the big-spending Rossoneri are targeting a permanent deal or a short-term loan.