The Spain international looks set to make a return to Atletico Madrid, and the Italian boss has suggested the situation is now closed
Antonio Conte has indicated that he decided in January to allow Diego Costa to leave Chelsea.
Conte and Costa reportedly fell out after the Italian refused to let the striker join Chinese Super League side Tianjin Quanjian.
Costa was subsequently dropped from the Chelsea squad for the Premier League game against Leicester City, although he returned to help Conte's men claim the Premier League title, scoring 20 goals over the course of the campaign.
The Spain international is now widely expected to leave Stamford Bridge, with a return to former club Atletico Madrid mooted, and Chelsea are on the brink of signing Real Madrid striker Alvaro Morata as his replacement.
Costa is not with the Chelsea squad on their pre-season tour of Asia and Conte gave the clearest indication yet that the 28-year-old will be sold.
"I don't like to talk about players who are not here," Conte told reporters ahead of Saturday's game against Arsenal in Beijing.
"The only thing I can tell you is that in January, the Costa situation was very clear, for the club for him and his agent. For me, the situation is closed."
While a return to Atletico appears Costa's most likely move, the switch is complicated by the club's current transfer ban, which runs until January.