Former Sydney FC winger Chris Naumoff has alleged the A-League club may have known about a heart condition that forced him into retirement at the age of 21.
After three seasons with the Sky Blues, Naumoff -- a former Young Socceroos and Olyroos representative -- penned a dream three-year deal in June with Spanish second division side Numancia.
However, the move was scrapped after a routine medical examination revealed he suffers from hypertrophic cardiomyopathy, a genetic disease which can trigger death when the heart is put under extreme stress.
It is the leading cause of death in young athletes.
Naumoff wants to know why it took a trip to Spain to find out and whether Sydney FC were already aware.
"The question was asked and in terms of getting an answer from whoever needs to answer these questions, [it] is still up in the air," Naumoff told SBS.
Cardiac screening and electrocardiogram (ECG) tests are recommended by Football Federation Australia but were not made compulsory until the A-League's latest collective bargaining agreement was introduced last year.
Under the new rules, players are supposed to be barred from training until their club conducts a specific set of health check-ups, including an ECG.
Naumoff says the only ECG he ever had at Sydney was in February -- more than halfway through the season -- and he heard nothing back.
- Kiki Naumoff (@cnaumoff29) August 29, 2016
"So as you would guess, I thought everything was fine," Naumoff said.
"The results [in Spain] did show that there was something wrong with my heart and that I did need further testing. I wasn't made aware of this.
"Why that's the case? I'm not sure. But this is definitely a thing that's on the results and something that should have been taken further at the time."
Naumoff played six more games for Sydney between his ECG and his move to Spain.
The club told SBS it was "saddened" by Naumoff's retirement and it had offered him a new 12-month contract but said medical records of players were confidential.
AAP has contacted Sydney FC for further comment.