The six-goal rout at Stamford Bridge was City's biggest loss since 1995 and the worst of Eriksson's entire managerial career.
"The goals we conceded got easier and easier.
"I still believe we are still a very good team with very good football players. But it is very difficult to explain what happened at the weekend. It was a collective collapse, truly awful.
"I was sat on the bench with 20 minutes to go, looking at my watch wishing it was finished because I knew there was no chance we would come back.
"We saw exactly what happens when you are not prepared to defend properly against the likes of Drogba, Lampard, Essien and Joe Cole.
"If you give them all the space of an airport they will kill you and they killed us."