LONDON: Chelsea have told Diego Costa that, if he wants to rejoin Atletico de Madrid, the first step is to end his exile, return to London and prove his fitness with the Premier League champions.

Costa has criticised Chelsea’s treatment of him this summer, and said he is prepared to remain in exile for a year. He said in a weekend newspaper interview that he felt he was being treated like a “criminal” by the club.

The player has two years remaining on his contract and the Premier champions want the Brazil-born Spain striker to prove his fitness and make himself available for selection, even though he is no longer in manager ¬†Antonio Conte’s plans.

After being granted an additional week of leave and missing the pre-season tour to Asia, Costa is still to return to London around two weeks after his anticipated arrival.

Costa, speaking at his family home in Lagarto, Brazil, said he has not reported for training as he does not want to train with the Blues’ reserves, and is happy staying in Brazil and paying club fines until his future is resolved.

Costa joined Chelsea from Atletico in July 2014. He has twice won the Premier League title during his three years at Stamford Bridge and scored 59 goals in 120 appearances. The 28-year-old claims he was told he was not wanted by Conte by text message in the summer.

The Blues declined to respond to Costa’s comments.

Chelsea and Conte have previously insisted the decision for Costa to leave this summer was made in January, with both the player and his agent, Jorge Mendes, aware.

Atletico are under a transfer embargo and cannot register new players until January.