Bidding to win their first European trophy since a Diego Maradona-inspired side won the old UEFA Cup in 1989, Napoli host the English Premier League side on Thursday in the second leg of their tie, trailing 2-0 from last week's first match.
"In three words, we need courage, intelligence and heart," Ancelotti told reporters. "I saw only a little courage in the early stages of the first game. Intelligence, I saw in both halves of the match. Heart is something we will put in tomorrow.
"In addition, we need a significant dose of intensity. We must seize this opportunity, we need a positive mental attitude and, I repeat, a lot of heart. And there will be an extraordinary environment to drag us."
Napoli went into a so-called "ritiro" -- where the team are confined to the club's training complex or hotel -- after their 3-1 Serie A win at Chievo on Sunday, although Ancelotti said he was not in favour.
"Were the players against it? No, in reality, it was me who didn't want it," he said. "Generally, I'm against the 'ritiro', because I think the players are better off at home than on the computer or social media."
"Napoli are the only (Italian) team left in Europe and I hope that is still the case on Friday," he added. "Napoli will put in a great display tomorrow - I believe we can do it."
(Writing by Brian Homewood; Editing by Christian Radnedge)
