Barry Bennell, the UK ex-youth football coach and convicted paedophile, has been taken to hospital after being found unconscious.
The 62-year-old was found at a property in Stevenage after a 'fear for welfare' call was made.
Bennell, who worked in coaching for several teams, including Manchester City and Stoke, was given a four-year sentence for raping a British boy on a football tour of Florida in 1994 and a nine-year sentence in 1998 for 23 offences against six boys in England.
Last week several more former players came forward with allegations of historical child abuse, prompting the Football Association to step up its review.
The scale of the issue has grown by the day since former Crewe player Andy Woodward waived his anonymity to speak about his abuse at the hands of Bennell.
Professional Footballers' Association chief executive Gordon Taylor expects the number of allegations to continue rising.
He told BBC Radio Five Live's Sportsweek programme: ''From that time, of those who became apprentices and senior players, over 20 players have come forward."
Asked to name the clubs that had been connected to allegations, Taylor said: ''We'd start at Crewe, go to Man City, Stoke, Blackpool, Newcastle, Leeds... I'm expecting there will be more. I think we have six or seven clubs.
''I can't believe it's just going to be in the northwest and northeast. We need to be mindful this could be throughout the country in the same way it's been in other professions where children are there - in the church, in schools and other areas we are well acquainted with over the past few years.''
The Metropolitan Police, Hampshire Police and Cheshire Police have said they are investigating allegations of abuse in the football community.