Kacper Potulski

Based on available data, the player's market value was listed by Transfermarkt at €18 million in June 2026. In May 2026, reports claimed Borussia Dortmund submitted a €20 million offer that was rejected by Mainz, who reportedly demand a higher sum. Earlier, in March 2026, unofficial reports suggested a possible transfer fee could be between €15 million and €25 million.

Our valuation for Kacper Potulski is primarily shaped by a reported, but rejected, €20 million offer from Borussia Dortmund in May 2026, which sets a clear floor for negotiations. Combined with earlier unofficial reports suggesting a potential fee between €15 and €25 million and widespread interest from top clubs, we anticipate Mainz will hold out for a figure in the mid-twenties, leveraging their strong position with his contract running until 2028.