The Dortmund and Norway striker has been heavily linked with a Premier League move, and has worked with Ole Gunnar Solskjaer in the past at Molde.
Hamann told Stadium Astro: "I don't think Haaland is a Manchester City player. I can't see him joining Man City and I'm not sure whether City will be interested in him.
“Pep [Guardiola] has got rid of some centre-forwards in the past. The way they play, they like to pass the ball around, I'm not sure whether Haaland would suit Man City or fit in there.
“At Manchester United, they have so many quick players and like to counter-attack, I think Haaland will suit United a lot better than City.
“Can United get him in the summer? I think there might be a situation in the summer if Dortmund miss out on the Champions League, where they might have to sell Haaland and [Jadon] Sancho. I think they could both go in the summer."