Mino Raiola, the agent of Erling Haaland, has named Manchester City, Real Madrid, Barcelona and Bayern Munich as clubs the Norwegian star striker could join in 2022.
The 21-year-old has a contract with Dortmund until 2024, but his tally of 23 goals in 20 Champions League games for Dortmund and ex-club Salzburg has attracted Europe's top teams.
There is a release clause, reportedly for 80 million euros ($90 million), in Haaland's contract which becomes active in 2022.
Raiola has told broadcaster Sport1 there is "a great chance that Erling will leave" at the end of this season.
"Maybe this summer, maybe the summer after," Raiola added.
"He can - and will - take the next step. Bayern, Real, Barcelona, (Man) City - these are the big clubs he can go to.
"We all knew when we moved to Dortmund that this step would come."
The Italy-born football agent plans to sit down with club bosses at Dortmund in the coming months, adding: "We will say what our idea is and they will tell us theirs".
Haaland has sent goal records tumbling since joining Dortmund in January 2020.
He became the first player in Bundesliga history to score a hat-trick on his debut as a replacement and has since netted 51 goals in as many German league games.
Dortmund, who currently sit second in Germany's top flight, were knocked out of the Champions League during the five weeks Haaland was recently sidelined by a hip problem.
The injury also proved costly for Norway, who missed out on qualifying for the 2022 World Cup in Qatar when they lost 2-0 to the Netherlands last month when Haaland was sidelined.