Christian Heidel responded to rumors that top clubs like VfB Stuttgart are interested in Kacper Potulski. Christian Heidel stated that it is not their intention to release him and that he will not leave. Kacper Potulski is contractually bound until 2028. Christian Heidel emphasized that they will not release him for a small amount of money and that he must now play and establish himself as a regular player with them.

VfB Stuttgart is reportedly one of several Bundesliga clubs watching the circumstances of Mainz centre-back Kacper Potulski. Competition for the Polish youth international has begun, and while a move to the Premier League has been discussed, it is believed staying in Germany is more realistic. Borussia Dortmund is the current favorite to sign the player, who is said to be a high priority for them. Bayer Leverkusen is also named as a competitor, with Bayern Munich and Hoffenheim also watching the circumstances. Unofficially, it is said that a transfer fee could be between 15 and 25 million euros.