Kasey Bos transfer: what we know
Kasey Bos's move from FSV Mainz 05 to Excelsior is recorded as completed, with the database showing a loan transfer.
The TransferNews database currently lists Kasey Bos as moving from FSV Mainz 05 to Excelsior. The record is classified as a loan move and carries a status of completed.
The move is recorded as a loan and no separate reported loan fee is attached. The recorded transfer date is July 1, 2026.
This dossier links the move to 1 supporting report. Player, club and league profiles below provide the wider transfer history and current market context.