Cahill's howler came after a similar incident led to Swansea City scoring in their 2-2 draw a fortnight ago.
“It is always a team problem rather than individuals, When nothing works it is very hard for a player to play well," argued Conte.
“I don't want to talk about the mistake [Gary Cahill]. it is not right for the player. We win and lose as a team.
“If someone thinks this team is ready to fight, I think we must wait to improve a lot to come back a great team on the pitch, not just on paper.
“We have not got the balance and now is the moment to consider everything. It is incredible to concede three goals.
“We must have last season present in our mind to not repeat the mistakes. We must reflect a lot to find very soon the right way."