The former England coach claimed his side's poor performance helped to make Chelsea look better than they were.
"My worst result previously was Gothenburg - 5-1 to Arsenal many years ago in the European Cup Winners' Cup.
"Maybe there has been too much talk about us playing good football and I will not blame anyone, absolutely not. But if you don't defend well in football then things will happen that have happened today.
"We made Chelsea better than they are today. By two or three passes they are along with our goalkeeper - that is not defending.
"I am not talking about the four defenders, I am talking in general. If you defend in football today, you have to defend with 11. We did exactly the opposite."