They have been friends since Larsen was 16 years old. "We are close friends on the national team," Larsen said. When asked if they talked about the upcoming game, Larsen replied, "Of course. I jokingly tried to intimidate him about playing at Molineux, but he wasn't fazed. I'm still trying to mess with his head a little bit."
Larsen, who signed for Wolves in the summer, is in awe of Haaland's record. "It is insane." He is trying to learn from him but admits nobody really compares. Any advice for the Wolves defenders? "They probably know his strengths already. He is a machine."
But Larsen is an impressive figure himself, a 6ft 4in striker who would doubtless be leading the line for Norway in another era. He scored 13 goals in LaLiga for Celta Vigo last season and has found the net twice for Wolves with instinctive first-time finishes.
Unfortunately, both were in defeats - there have been six in seven games so far, with Wolves still looking for their first win. "We are not where we want to be. I believe so much in this team, so I think that is going to turn, but it needs to happen very soon."
TrendingIndividually, however, there are encouraging signs that Larsen brings something that Wolves were lacking last season. He is the natural number nine that they wanted, giving Gary O'Neil more options in the build-up. His strong hold-up play has been promising.
Indeed, no player in the Premier League has held the ball up as many times as Larsen this season - he is doing so 50 per cent more than anyone else, in fact. "It is a good statistic to see!" The idea is that this gives Wolves a platform in the opposition half.
"Sometimes you cannot always play out as a team," Larsen explains. "And you need a big striker to be strong. I am a tall guy. I need to be able to hold the ball up, so I think that is really important for me as well, and I even want to improve it even more."
He understands why he has been brought in. "I am a different number nine to what had been here last season, where they were playing with more of a 10 as the striker." He believes he does his best work inside the box. "That is where I like to be," he explains.
"I am a hard-working striker. I think that I always compete for every ball like it is the last ball, and I think that is what my team-mates also know. I am quite fast, quite strong, so I have many different attributes to bring. But the most important thing is to score goals.
"In the first seven games, I am already understanding a bit how I should play to score more. I have got my first few goals and some goal involvements, that is really important for a striker. But it is easier when a team starts to win, then it is also easier for a striker."
There has been nothing easy about leading the line for Wolves so far this season. His first goal came in a 6-2 defeat, his second in a 5-3 reverse. At least they are scoring, Larsen even helping to set up a goal against Liverpool after besting Ibrahima Konate.
Facing Konate and Virgil van Dijk ahead of another test against the likes of Ruben Dias and Manuel Akanji this weekend, sums up the scale of the Premier League challenge for one fresh to the competition. His introduction was against William Saliba and Gabriel.
"Some good defenders already! Of course, some are better than others. But I had a big chance against Arsenal and a half-assist against Liverpool so I am not scared of them. You come here to compete and I am going to work hard to punish them even more."
It is a step up but Larsen is accustomed to that. He left Norway at the age of just 17 to pursue an opportunity at AC Milan. "My mum was not happy, moving all the way to Italy alone." But he was following his football dream, Zlatan Ibrahimovic having been a hero.
"I was always good, a big talent as a kid and I had a lot of interest from club academies when I was growing up. Milan came knocking at the door and I felt like I had to just jump in and do it. It was a new culture, a new world actually, because no one spoke English."
He learned Italian within six months and went on to take a lot from the experience, returning to Norway before moving on to FC Groningen in the Netherlands and then Celta Vigo. "Every step that I have made since that first one, it has been easier," he says.
"That is why I feel really comfortable already now, so I think that has helped me a lot. I take it with me also when things are tough like in this situation right now. I know that it is going to turn and it is only about sticking together and working hard as a whole team."
That was his experience in Vigo, where the team's poor form left them in trouble in the spring before clambering to the relative comfort of 13th - thanks to Larsen scoring goals in the final 15 games. "We fought relegation but I really enjoyed my time there."
Fernando Torres, like Ibrahimovic, had been another hero of Larsen's when he was younger - even naming his cat after the striker. Working with Torres' former Liverpool manager Rafa Benitez while at Celta Vigo was an important step in his development.
He credits the influence of Benitez in helping him to find the space to free himself of defenders. "Those details, he taught me a lot of movements inside the box. It is why I scored so many goals." And he sees a similarly detail-led approach from O'Neil.
"He has been helping me a lot. The things that I am already doing well, we're trying to make it world class. That is where I want to be. I want to be as good as I can be for the team and for myself, so him helping me on the side has been really important."
What sort of work? "A few times when I am controlling the ball, it feels like I have more time than I actually have. I think the finishing comes with time as well. I need to get used to the league. I am getting there, but it all happens quicker. We work on those things."
The impression is of a player who is enjoying so much about this experience. He talks of feeling "really at home here" and his language skills - Larsen is also fluent in English and Spanish - mean that he has settled in quickly among his new Wolves team-mates.
"I feel really welcomed, I feel like this is a good place for me to be. But you have to be patient as well. I cannot expect to come in here and score in every match and be the hero every time, so I am going to have to take it step by step and try to change it in time."
But that is the crux of it. With Wolves bottom, things do have to change and Larsen needs to help change it. He admits double figures is a benchmark for a striker but the priority now is winning. "You cannot say we have been unlucky every game," he says.
"We have been unlucky in some situations and not good enough in others. I think it is small details. That is the good thing. We have been creating chances, scoring goals, and that is easier to continue with. Then it is about closing it a little bit more at the back.
"It is not about the defenders doing it wrong, it is about the whole team. We have to stay together more, be compact. I think that the small details will change it all. But when you are in the kind of zone that we are in now, everything goes a little bit against you."
There would be no better time to change that than against Manchester City on Sunday. "It would be a very good time," agrees Larsen. Standing in their way, however, is the man, the machine, the monster, who he knows so well. "Hopefully, we can stop him."
Watch Wolves vs Man City on Premier League this Sunday from 1pm; kick-off 2pm