The Italian side are currently top of Group C with nine points and can book their place in the knockout phase with a draw in Tuesday night's heavyweight encounter.
Mertens has experienced the Anfield atmosphere on a European night already, as a Utrecht player 10 years ago in the Europa League, and he has questioned the ground's famous reputation as one of the toughest venues to play at in European football.
“My strongest memory is that they have a sign saying ‘This is Anfield’ and everyone was talking about it, so I was thinking it’s very big, you know,” he told The Times.
“I came through the tunnel and I asked, ‘Where is the thing?’ and they said you missed it and I hadn’t noticed it.
"So, in the second half, I’m looking at this small thing and asking, ‘Is this so special?’"
The 31-year-old winger went on to concede that he expects a far more raucous crowd than the one he encountered on his previous visit to Anfield but also insists he can cope with the pressure to elevate his own performance.
He added: "Football in Italy is crazy and the people are very crazy, too, so I think we are used to it. For me, it will push me to a different level, these are the nights we want to play."
Liverpool also head into the crucial Group C clash full of confidence, having reached the Premier League summit with a 4-0 win at Bournemouth at the weekend.