Liverpool kickoff their Champions League group campaign this week with a clash in Amsterdam.
Westerveld told Voetbal International: "If you see how they played at Real Madrid (in 2019).
"That was a team that stood out. And they played well. They were not sorry about anything. It didn't matter where they played, they played the Ajax-style. Whether it was at the Santiago Bernabéu or at home.
"But now there is a lot going on, the quality has been lost in the last seasons with all those guys who have been sold.
"I also think Liverpool is one of the top three teams in the world at the moment.