Up to 13 players have failed routine drugs tests over the last four years but their identities have been kept secret by the Football Association, according to a report.
Last week it emerged that Stoke City striker Saido Berahino had served a secret eight-week ban while at West Bromwich Albion after allegedly testing positive for the party drug MDMA.
According to the Daily Mail, as many as 13 other footballers have tested positive for recreational drugs - including cocaine and ecstasy - since 2012 but have been protected by the FA as "it helps support their rehabilitation".
The organisation took 2,442 samples from players last season and hopes to increase the number to 5,000 by 2018.
From the 13 positive samples, two are thought to relate to ex-Sheffield United midfielder Jose Baxter, while goalkeeper Aaron McCarey was named and shamed by Wolverhampton Wanderers, his club at the time, in 2015.
