Jordan striker Ahmad Hayel developed hypothermia after being made to drink "several litres of water" by doping testers at the Asian Cup, according to his country's football association.
The 31-year-old drank so much water to help him give a urine sample following the 1-0 defeat by Iraq.
Jordanian FA general secretary Fadi Zureikat said the procedure left Hayel in a "semi-coma and with hypothermia".
Asian Cup officials said they were waiting for a report into the incident.
Zureikat claims Hayel was given no salts or minerals with the water and that the forward was unconscious when taken back to the team hotel in a private car.
Jordan manager Ray Wilkins, the former Chelsea coach and England midfielder, described the incident as "dangerous". He could be without Hayel for Friday's match against Palestine in Melbourne.