Jurgen Klopp believes Liverpool need a "special" performance to overcome Napoli in the Champions League on Tuesday night.
A 1-0 or by two clear goals victory over the Serie A is needed for Liverpool to advance to the knockout stages.
And Klopp knows it will be no easy task after losing to Carlo Ancelotti's side in Naples.
"It is a big task. Napoli did so well with Maurizio Sarri and now they have such an experienced manager in Carlo Ancelotti, who has come in," Klopp said.
"In the summer when we played them in a pres-eason friendly, he was already full of praise about the club and its staff.
"He was talking about little changes he wanted to make and that is really tough after a very demanding coach like Sarri, making changes and keeping the players behind you after being very successful.
"You can see the differences and they are so good. They do really well in the league.
"We all know the results we need. It is difficult because Napoli is good in possession but is good counter-attacking as well and a typical Italian team, good at defending.
"So it is a big challenge but it is football and if something special is possible, it is here."