Barnsley have been ordered to pay Hull almost £1m after being found to have failed to disclose medical information during the transfer of Angus MacDonald.
Hull successfully argued to an independent arbitration panel that they would not have signed MacDonald if they were aware of his full medical history.
The panel found that there had been no dishonesty from Barnsley.
The case ended up at a tribunal after Hull refused to pay the remaining £200,000 instalment of the £600,000 fee they agreed with Barnsley for MacDonald the day before the transfer window closed, claiming breach of contract for failure to disclose "crucial medical information".