Dutchman Koeman took over 16 months ago and spent a significant amount of money overhauling the squad in the last transfer window, but Everton have won two out of nine league games in their worst start to a season since 2005-06.
“Everton Football Club can confirm that Ronald Koeman has left the club,” Everton said in a statement on Twitter.
“Chairman Bill Kenwright, the Board of Directors and Major Shareholder Farhad Moshiri would all like to express their gratitude to Ronald for the service he has given to the club over the past 16 months and for guiding the club to seventh place in last season’s Premier League campaign.”
Koeman arrived from Southampton in 2016 amid huge expectations and was granted the resources to revamp the squad in the last transfer window with a net spend of 54 million pounds.
But Everton have won two games in 13 in all competitions and produced another lacklustre performance against Arsenal, a defeat that led to boos and many fans leaving before the end.
Beyond the poor results, Everton’s supporters have been discouraged by a series of muddled displays with formations and players frequently switched as Koeman, an increasingly distant figure, struggled for cohesion.
“I haven’t seen a worse Premier League side this year,” said former player and BBC pundit Steve Claridge. “It feels like it’s stale, the players here aren’t of the quality needed, there’s not a set system, not a pattern of play.”
No wonder Kenwright was pictured with his head in his hands in the directors’ box on Sunday. Alongside him, Moshiri took the decision to sack his second manager in 16 months following the departure of Roberto Martinez.
(Reporting by Neil Robinson and Simon Jennings, editing by Ed Osmond)