Everton manager Ronald Koeman left Kevin Mirallas out of Chelsea loss due to concerns over attitude

Everton manager Ronald Koeman left forward Kevin Mirallas out of the side that suffered a 2-0 defeat by Chelsea due to concerns over his attitude, the Dutchman revealed after the clash at Stamford Bridge.

Mirallas had been expected to be a part of the Toffees' set-up in west London on Sunday (27 August), but was instead allowed to fly to Belgium in order to join up with his national side a day early. There were suggestions that the 29-year-old was attracting interest from former club Olympiacos, but Everton do not want to part with Mirallas with just a few days of the transfer window remaining.

Mirallas has only started two of Everton's competitive fixtures this season and has been afforded just 13 minutes of Premier League action so far.

Koeman said Mirallas is "struggling to deal with moments" in the embryonic stages of the new campaign and was seemingly left with no choice but to drop the former Lille forward on Sunday.

"He was out because he is struggling to deal with moments in the season and was disappointed," Koeman told the Liverpool Echo.

"Everybody can be disappointed, but I expect from everybody to be part of the team. If somebody is showing that he is disappointed and his attitude is not the same then I have to make decision."

Asked if Mirallas will remain an Everton player after the transfer window, Koeman said: "I don't know."

Mirallas joined Everton from Olympiacos in the summer of 2012 and has since gone on to make 177 appearances for the Merseysiders, scoring 39 goals. The versatile attacker is a rather divisive figure among Toffees supporters and has failed to truly flourish during his five years at Goodison Park, with injuries and inconsistency hampering his chances of regularly delivering on his obvious talent.

Olympiacos had hoped to lure Mirallas back to Greece on loan but Everton are more focused on signing attackers rather than selling them. Koeman reiterated his desire to see a new striker arrive on Merseyside before the end of the transfer window, but a move does not seem to be imminent.