A High Court judge has ruled that Tottenham Hotspur breached its duties to a 17-year-old footballer who suffered cardiac arrest in his first game for the club and was left brain damaged.
Radwan Hamed, now 26, collapsed during a youth team game in Belgium in August 2006.
In a screening before he signed for Spurs, an ECG showed his heart to be "unequivocally abnormal", but he was not stopped from playing.
Mr Justice Hickinbottom said: "In addition to the usual obligations of a doctor to a patient, the FA protocol placed an obligation upon them to ensure that the claimant and his parents were made aware of any risk that the claimant faced.
"It was their responsibility, as specialist physicians and employers, to ensure that relevant risks were identified and communicated to the claimant and his parents to enable them to make an informed decision as to whether to bear them. In this, they singularly failed."
Damages, which could reach £7m, are to be decided next week.