Diego Costa timeline
Striker Diego Costa is set to return to Atletico Madrid from Chelsea after the two clubs agreed a fee reported to be £58million.
The 28-year-old moved to Stamford Bridge from Atletico for £32million in July 2014, signing a five-year contract, and has won two Premier League titles and the League Cup in three seasons with the Blues.
Here is a timeline of the events which led to his exile from Stamford Bridge.
January 13: Costa does not travel with the Chelsea squad to Leicester for the following day's fixture after reports of a behind-the-scenes bust-up with Antonio Conte and his backroom staff amid suggestions the striker's head had been turned by a mega-money offer from China.
January 14: Without Costa, Chelsea win 3-0 at Leicester. Conte insists the reason for the striker's omission was a back injury, saying: "I like to tell the truth, and that is Diego stopped training on Tuesday. He didn't train in the week because he wasn't fit."
January 16: Costa trains on his own for a second successive day after missing the Leicester match, while his first-team colleagues enjoyed two days off.
January 17: The owner of Tianjin Quanjian, who had been linked with a mega-money offer for Costa, says new rules in the Chinese Super League have altered their recruitment plans. But speculation gathers of a return to Atletico Madrid.
January 20: Conte says Costa is available to play against Hull. The Italian adds: "I think the player wants to stay at Chelsea. He's very happy to play with us. This idea (to move) is far from his mind. I'm sure about his commitment, his behaviours, his will to fight with this team, to try together to fight to the end to try to win the title."
January 22: Costa is restored to Chelsea's starting line-up at the first opportunity and scores his 52nd goal on his 100th Chelsea appearance in a 2-0 win over Hull. Conte says: "I hope with this game to finish the speculation about him, about Chelsea, about me and him. We showed we are a team with great unity."
January 31: Costa has a penalty saved in a 1-1 Premier League draw at rivals Liverpool, on transfer deadline day.
February 3: With the Chinese Super League transfer window still open and thoughts in Europe turning to the summer, speculation continues to swirl around Costa. Conte says: "Every week I hear a lot of news, a lot of speculation about Diego. I think now the most important thing is to be focused on this championship."
February 17: Conte says the future of all his players, including Costa, will be discussed at the end of the season as the focus should not waver from winning the Premier League title.
May 8: Costa scores his 20th goal of the Premier League season in a 3-0 win over Middlesbrough which takes the Blues within reach of the Premier League title.
May 27: Chelsea lose the FA Cup final 2-1 to Arsenal. Costa scores his 59th goal for the Blues on his 120th appearance.
May 28: Costa insists he does not wish to move to China and only wants to move to Atletico if he leaves Chelsea. "I have no intention of leaving, I'm very happy here, I have two years on my contract, but if the club want to sell me there is one club I would go to," Costa says.
June 8: Costa says Conte sent him a text message to tell the striker he is not in his plans next season.
July 21: On Chelsea's pre-season tour to Asia, without Costa, Conte says the decision to cut the striker from his squad was made in January. The player and his agent, Jorge Mendes, were aware. "The situation is closed," Conte adds.
August 4: A lawyer stating he represents Costa threatens legal action after the striker was told he was free to leave. Chelsea describe claims Conte is forcing out Costa as "just nonsense".
August 11: Chelsea and Conte are tight-lipped on Costa as it emerges legal proceedings are taking place behind the scenes.
August 14: Costa criticises Chelsea's treatment of him this summer in an interview with the Daily Mail. He says he is "not a criminal" and is prepared to remain in exile in Brazil for a year.
August 17: Repeats his wish to return to Atletico, and says he believes the situation will be resolved upon his return to Spain.
August 18: In an interview with ESPN Brasil, Costa pleads with Chelsea to lower their asking price to allow him to return to Atletico.
September 21: Atletico and Chelsea announce an agreement has been reached for the player's return to Spain after the Premier League club accepted a reported fee of £58m for the striker.