The boss of our Europa League visitors admitted he watched only half of the Anfield game live on TV - the half in which United could have taken the lead.
"It really was unbelievable," said Pellegrini, when a reporter requested his reaction to the shock scoreline.
"I was watching the first 45 minutes because after that we had to play against Real Madrid so I couldn't see when Liverpool scored the other six goals.
"But of course I understood immediately what would happen at Manchester United. In their rivalry with Liverpool, for them to concede that amount of goals, it would not be easy for them.