Everton boss Ronald Koeman was fiercely critical of his side after their FA Cup third-round exit against Leicester.
The Dutchman suggested the 2-1 defeat should serve as a wake-up call at the Merseyside club in terms of the need for squad strengthening and general improvement.
Three days on from their major shareholder Farhad Moshiri speaking of his ambitions for the Toffees at their general meeting, Everton - who last lifted a trophy when they won the FA Cup in 1995 - went out of the competition at Goodison Park.
They grabbed the lead just after the hour mark through Romelu Lukaku but Leicester swiftly hit back via a quickfire brace from substitute Ahmed Musa.
And Koeman said afterwards: "In my opinion it is not bad luck - we did it by ourselves.
"We were 1-0 up and it was unbelievable how we dropped back. Lack of concentration, maybe.
"We did the most difficult thing, scoring the goal, because Leicester were really defensive, and I don't understand why we then lost the game - there was no reason.
"But if you play like we did after it was 1-0, then you ask for goals against."
Everton's next game is a Premier League home clash a week on Sunday against Manchester City, who thrashed West Ham 5-0 at the London Stadium on Friday.
And Koeman added after his team's loss: "If we play like the last 30 minutes, it can be the same result as yesterday, West Ham. We need to do better and improve."
Koeman's mission to rejuvenate Everton following his appointment last summer currently sees the club lying seventh in the Premier League.
The Dutchman - who has lost the biggest signing he made in the last transfer window, Yannick Bolasie, to long-term injury - has brought in teenage winger Ademola Lookman from Charlton so far in January.
He hopes to make Morgan Schneiderlin another addition in this window, and has also expressed his interest in the midfielder's Manchester United team-mate, forward Memphis Depay.
Koeman said "I don't know" when asked after the Leicester game if there had been any progress in terms of Schneiderlin and Depay.
But he did say: "I know what we need to change. If everybody opened their eyes today, maybe we will get further in our improvement as a team, because that is really what the team needs, and okay - that is all about what happens this month.
"I have that (bringing new players in) in mind and the board knows because we spoke together about what we need and the team needs.
"That is the job of (Everton director of football) Steve Walsh, and it is my job.
"And I hope everyone realises what the team needs to play and get results, what the expectations are in this club.
"I could explain more, but I don't like to because that is really talks we need to do inside.
"But if a young player of 19 (an apparent reference to 18-year-old Everton midfielder Tom Davies) is today one of the best on the pitch, I think that says enough."
Leicester boss Claudio Ranieri delighted in his side gaining "revenge" for their 2-0 Premier League home loss to Everton on Boxing Day.
And he compared summer signing Musa - a first-half substitute for Leonardo Ulloa now with four Leicester goals to his name - to Jamie Vardy, who Ranieri hopes will make his return to action against Chelsea next weekend after missing out here due to illness.
"I was very pleased with our performance," Ranieri said.
"We wanted to win, to go through in the FA Cup, because it is an important competition - and more, because we lost against Everton at home. We wanted revenge.
"It was important for Musa. Maybe now he understands better the Premier League - the fighters.
"He was a very good threat - similar to Jamie Vardy. Everybody was scared when he attacked the space!"