The Canaries boss admitted that his players gave Luis Suarez - who found the net four times - too much space during the match.
"We could defend better. Suarez is a world-class player and you look at the type of goals that he scores and he can score the type of goals most other players can't," he told Sky Sports News.
"But if you afford him the time and space that we did on the goals then it makes life very, very difficult for ourselves and somebody of his quality is certainly going to capitalise on that.
"There aren't many players who can score that first goal but the second goal was the one which hurt us as it was a soft goal."
Norwich lie in 16th place in the Premier League table following the heavy defeat, while Liverpool occupy fourth on goal difference.