Speaking to TV2, Virgil van Dijk said: "It's definitely not easy — Erling Haaland has been on fire, you can't say anything else. I remember after the Community Shield where a lot of people have been writing him off.
"I remember I was saying, 'listen, this guy is going to cause so many defenders nightmares'. He's shown it, he's been showing a consistent level and in a team like Manchester City where chances will always come.
"We have to try to stop the balls going to him, defend at the highest level, and be at our best, and that's what we always have to be against Man City and that's not going to be any different on Sunday.
"It's something we should look forward to, it's definitely not me against him, it's all of us versus all of them. It’s the outside world that creates battles, one versus one. We want to stop them scoring, regardless of who it is on the pitch.
"But we know Haaland is quite good. He's a very good goalscorer, let's keep it that way, and hopefully we can stop him from scoring on Sunday, we need to be at our very best to do that, but like I said, it's all of us versus all of them."
Liverpool host Man City in the Premier League on Sunday and Haaland will be looking to score his first goal against the Reds after failing to find the net in the Community Shield clash back in August.
Since then, the 22-year-old has been on fire for Pep Guardiola's side, scoring 20 goals in just 12 games across all competitions as they sit just one point behind first place in the top-flight table.
