Bayer Leverkusen is interested in Fedde Leysen, a Belgian defender from Union SG. It is reported that VfB Stuttgart and Eintracht Frankfurt are also monitoring the 22-year-old left-footed player, and Stuttgart is said to be particularly keen on signing him. This interest from Bundesliga clubs exists despite Leysen being a substitute at Union SG. For Union SG, he has made 23 appearances, scored one goal, and provided one assist in the 2025/2026 Jupiler Pro League season. The defender has also been capped twice for Belgium's U21 team. West Ham United, Napoli, and Fiorentina have also been previously linked with the player. A potential transfer fee of €15 to €20 million has been mentioned, although this is considered unlikely because his market value is estimated at €5 million. In August 2025, Union SG reportedly demanded over €10 million. Leysen has a three-year contract remaining at the Belgian club.