Diego Costa said he is disappointed Atletico Madrid did not wait long enough for him to force through a return as the Chelsea striker vowed never to fight to come back to the LaLiga club.
Costa came close to leaving Chelsea in the off-season after seriously considering a return to Atletico for family reasons heading into the 2016-17 campaign.
The 28-year-old Spain international stayed and has starred under head coach Antonio Conte - who permanently replaced Jose Mourinho - scoring 17 goals to help Chelsea move 10 points clear atop the Premier League standings.
However, Costa revealed how desperate he was to make it back to Vicente Calderon, where he left for Stamford Bridge in 2014.
"The relationship with Conte did not begin well because on arrival I told him that I wanted to go to Atletico," Costa told Cadena Ser.
"I did everything possible to return to Atletico. I won't fight like that to return again.
"When Atletico had to wait for me they didn't. There was still a month of the market to go."
"When Atletico did not wait I went with the tail between the legs to speak with Conte."
While a return to Atletico appears out of the question and a move to city rivals Real Madrid impossible, Costa refused to rule out a switch to the lucrative Chinese Super League.
Costa was the subject of intense interest from the CSL in January and February, with Fabio Cannavaro's Tianjin Quanjian leading the race for his signature.
"Do not rule out anything," added Costa, who is preparing for a World Cup qualifier against Israel and an international friendly in France.
"It is almost impossible to go to Madrid with the relationship I have with Atletico.
"In life, everything can happen, and I do not close the door to anything. Right now I'm good at Chelsea, I have two years left. I intend to fulfil my contract but you never know.
"It is not impossible to refuse it because there are things to value. Everything must be thought. I do not discard anything. If they come with something for Chelsea and the club tells me to leave ... I can go to China or another side."