Costa, 28, has failed to comply with his contract at Chelsea after opting against a return to training. His time at Stamford Bridge appears to be finished following Antonio Conte’s text, which outlined that the Spain international is no longer part of his plans. Conte has already signed Alvaro Morata from Real Madrid for £70m to replace Diego Costa, who wants to re-join Atletico Madrid once their transfer ban is lifted in the New Year. But Everton boss Koeman has left the door open for a possible deal for Costa after admitting that he would consider a temporary deal despite laughing off Joey Barton's loan claim.

Chelsea outcast Diego Costa trains on his own in Brazil Wed, July 26, 2017 Chelsea outcast Diego Costa has been training on his own in Brazil Play slideshow 1 of 5

Of course you like to sign players for the future, but if you can get the best one that way, then why not? Everton boss Ronald Koeman on Diego Costa deal

Koeman said ahead of Thursday’s Europa League first-leg playoff against Hajduk Split that will decide who reaches the group phase: “Of course you like to sign players for the future, but if you can get the best one that way, then why not?” The Everton boss, who completed the club-record £45m signing of Gylfi Sigurdsson from Swansea yesterday, wants to sign another striker. Koeman has given up hope of signing Arsenal striker Olivier Giroud and admitted finding a suitable No.9 to fill the void left by Romelu Lukaku is a struggle. “It’s difficult ­because it needs to be a quality player, or a young player who can develop or improve.

GETTY Everton boss Ronald Koeman has refused to rule out a move for Chelsea striker Diego Costa