Tottenham boss Ange Postecoglou admitted disappointment after their 2-0 defeat at Chelsea.
Trevoh Chalobah and Nicolas Jackson struck the goals for the Blues on Thursday night.
Postecoglou later said: "It wasn't good enough and I have to take responsibility for that, it is on me. I am the manager and I am the one putting them out there and it was not good enough.
"When we put in a performance like we did in the first half it meant my message wasn't getting through.
"We didn't play well, do you want me to write you a dossier of where it went wrong?
"I feel like we've lost a bit of belief and conviction in our football and that is on me to change that.
"It wasn't about conceding the [first] goal, it was our approach to playing football and we were nowhere near good enough. That is on me.
"We've been in a bit of a grind for a while now, that is part of our challenge and part of our growth. We have to go out there and perform and sometimes you have to grind out. We were poor today."
Asked if the top four was now out of the question, he added "I don't now how to answer these questions. We were poor today, what is the point of thinking about anything else? My responsibility is to make sure we play better next time."
