Cox suffered a life-changing brain injury before Liverpool's Champions League semi-final clash with Roma back in April.
The father-of-three suffered a severe beating, with Mr Cox's brother Martin saying that he can no longer speak or sit up without assistance as a result of the attack.
Earlier this month Filippo Lombari, a 21-year-old Roma fan, was cleared of participating in the attack on Mr Cox, but was charged with violent disorder.
Another man is also understood to have been arrested in Rome in connection with the attack and is awaiting extradition.
Mr Cox is receiving treatment at the National Rehabilitation Centre in Dun Laoghaire, with friends and members of his fmaily having set a fund-raising target of €2m to pay for his care.