He celebrated his 24th birthday on Saturday, but in a statement released this afternoon, St Pat's chairman Andy O'Callaghan confirmed the shock news.
He said, 'It is a huge shock and disappointment to him that he has been forced to retire so suddenly but he has a young family and the consultations with the doctor left him in no doubt that this was the correct course.'
'We are upset to lose him as a player. However, our loss is nothing compared to the cruel way in which his career as a professional footballer has been cut short. St Pat's will retain his services in a coaching and promotional capacity.'
St Pat's contest the FAI Carlsberg Cup final next Sunday against Longford Town, and lost last night for the second time in the space of a week at Richmond Park, against old boss Pat Dolan and his Cork City side.
Saints' boss Eamon Collins added, 'Naturally we will miss him from the side. He brought something a bit special and would have helped our cause on Sunday.'
'However, I concur fully with the chairman that what matters most is that Charles is well and in a position to establish a new career in Ireland. Everyone at the club will do their best to help him on that road.'