RSC Anderlecht attempted to acquire Siebe Van der Heyden on a loan deal with an option to buy. However, according to Sasha Tavolieri, the transfer will not be completed.

RSC Anderlecht is actively searching for a left-footed central defender and has shown interest in Siebe Van Der Heyden, an ex-Unionist.

An unnamed English second division club has shown interest in Siebe Van der Heyden, who is seeking more playing time as he is currently benched at Mallorca. Van der Heyden is under contract with Mallorca until mid-2028, and the club is expected to demand compensation, having paid nearly three million for him a year and a half ago.