Milan coach Carlo Ancelotti believes Liverpool are the toughest team to play against in Europe.
The Reds overturned a 3-0 deficit to beat Milan on penalties in the Champions League final in 2005 and they have consistently impressed in the competition in recent years.
Liverpool thrashed Real Madrid 5-0 on aggregate last month to advance to the quarter-finals, while they are also mounting a challenge for the Premier League title.
The Italian has great respect for Rafa Benitez and feels that Liverpool can be unstoppable at times.
“Liverpool are the hardest team to play against in Europe,” Ancelotti said in the Daily Mirror.
“Benitez is a great coach. He has a well-organised defence and the perfect counter-attack.
“To play against them is always dangerous. Manchester United are stronger, but they let you play. Liverpool don’t.”
Ancelotti, who has been linked with the manager’s role at Chelsea, has also paid tribute to Guus Hiddink.
He explained: “Hiddink is the coach I regard most highly. Professionally he is really good.
“He has done well everywhere he has gone. I like him as a person.”