Koeman faces questions after £140m spend
The Dutchman's side were tipped for a great season before proceedings began, but now look to be in a mire.
Ahead of the start of the season, optimism seemed rife at Goodison Park.
Despite the sale of former star man Romelu Lukaku, the summer saw their transfer window record smashed in a deal bringing Gylfi Sigurdsson to Merseyside, as well as the arrivals of strikers Wayne Rooney and Sandro Ramirez.
Now, the mood is very different.
Responding to Mourinho's comments that Everton were aiming for top four this season, Ronald Koeman's response was immediate: "Be realistic!"
The 'Toffees' are on a run of four straight losses, scoring in none of them and conceding a combined 13 goals across the spell.
Koeman is said to have held a meeting with senior players after their loss against Atalanta last Thursday, with the hope of getting to the root of the poor form on Merseyside.
Relationships with fans and indeed players could start to strain if Koeman doesn't come up with an answer soon.