Sean, from Dunboyne, was assaulted by a Roma supporter before Liverpool’s quarter-final tie against the Italian club 12 months ago.
He needed emergency surgery after suffering a bleed on the brain having suffered impact injuries to his head.
He spent many months in hospital following the attack and was later moved to a rehabilitation centre in Dublin.
Sean left care this week for the first time since the assault took place.
His brother, Martin, has told talkSPORT about the evening the events unfolded.
“I was actually with Sean that evening,” he revealed. The both of us had travelled over on the Tuesday morning.
“It was the biggest game of the season. We were buzzing to get there and had been there so many times down the years.
“It was horrific because I was standing beside Sean when the attack took place.
“It has just changed our lives upside down completely.
“At the very beginning I just thought that Sean was out cold and it just got more serious by the minute.”
He continued: “When the paramedics came and he was lying motionless on the ground we knew something wasn’t right.
“We were praying inside that he had just been knocked unconscious and we’d get to the hospital and Sean would wake up, have a bandage around his head and get out and say ‘what the hell was that all about, we missed a pretty big game’.
“It’s tough. It’s extremely tough. It has changed our lives completely.
“Day-by-day for Sean from the start was very hard as we didn’t know what road we were going down.
“Thankfully, since October, when Sean moved out to the National Rehabilitation Centre here in Dublin he has come on a lot.
“He’s getting the right rehab and the right facilities are there for him.
“There’s a long, long journey ahead and it is a massive struggle.
“The progress is slow and sometimes cruelly slow. At the moment there has been improvement.”
A Liverpool Legends vs Republic of Ireland Legends match has been organised for Friday evening to raise funds for the Sean Cox Rehabilitation Trust, with the likes of Steve McManaman, Robbie Fowler and Ian Rush taking part in the fixture at Dublin’s Aviva Stadium.
Sean Cox is set to attend the match, it was confirmed last week.
“It’s a milestone in Sean’s journey,” Martin added. “It was only recently the decision was made that he was well enough to come out.
“We don’t know how long he can attend the match for but he’s coming and that’s the main thing.
“Even if it’s half an hour or an hour, as long as he’s there as it is a milestone.
“Watching the Liverpool legends that myself and Sean grew up watching like Ian Rush and King Kenny is just fantastic and marvellous.
“They’ve given Sean such a massive boost as well.”