Diego Costa's expected move from Chelsea to Atletico Madrid is said to be a step closer after Diego Simeone agreed to commit his long-term future to the La Liga side by putting pen to paper on a new deal lasting until 2020.

Spanish radio station Cadena Cope says that the manager's decision is "directly linked with Costa's imminent move" to Los Colchoneros and Simeone demanded the return of the striker as an essential condition to sign the new contract.

Costa, 28, has been tipped to return to Atletico since the striker revealed in June that Chelsea manager Antonio Conte had informed him by text message that he was no longer part of his plans ahead of the 2017-2018 season.

On 21 July Conte confirmed that the player was going to be sold after the decision to part ways was in fact made back in January 2017.

"I don't like to talk about players who are not here. In January, the Costa situation was made very clear," Conte said in a press conference. "For the club, for him and his agent and for me the situation is closed."

AC Milan, Everton and other clubs were linked with his services during the summer but Costa made it clear that his desire was to go back to Atletico.

The Spanish international handed in the transfer request to force his exit and decided to stay on holiday in Brazil despite Chelsea ordering him to return to Stamford Bridge.

The move to Atletico seemed in question last week when Chelsea included Costa in the Blues' 25-man Premier League squad for the current season after the clubs failed to reach an agreement over his transfer – as Los Colchoneros cannot register him until January due to a Fifa transfer ban.

However, earlier this week the pendulum swung again as Costa was left out of Chelsea's squad for the Champions League amid renewed speculation that the Blues still expected to sell him to Atletico in January. The Spaniard would become ineligible to play for another club in the elite European competition if he plays with the Blues during the first part of the season.

Cope now contends that the saga is set to end imminently reporting that Simeone's new deal is the precursor to the striker's return to Atletico Madrid.

The Argentinian boss has publicly admitted that he wants Costa back at Atletico and the Spanish radio station claim that he asked the club for guarantees over the Spaniard's return before signing his new deal.

Cope says that Atletico have made a massive effort to tie Simeone to a new deal worth €15m-a-year (£13.7m, $17.9m), making him one of the best paid managers in the world.

Los Colchoneros are said to have also set a stunning €75m release clause in his contract in order to ward off potential suitors - with the likes of Inter Milan and Chelsea linked with the manager recently.

The lucrative deal is a clear sign of Atletico's belief in its manager and Cope understands that the next step to prove it will be to make another effort to bring the rebellious Costa back from Chelsea.

Diego Costa
Costa won the Premier League title with Chelsea during the 2016-2017 season. Getty Images