It was after a trip to Vietnam in 2015 that Cole contracted Focal Segmental Glomerulosclerosis and was quickly rushed to hospital upon his return to England.
United's 1999 Treble winning striker was reluctant to accept the kidney transplant, but a chilling discussion with doctors revealed that he had no option as his kidney function dropped below 10 per cent.
In his mid-40s, the former Manchester United striker was struggling to find any light in a world that had been turned upside down by a condition that forced him to undergo surgery, with his nephew Alexander the generous donor.
These were dark days for Cole, who admitted he "didn't know if he could get through" a health crisis that pushed him to the brink both mentally and physically.
Cole's famously unforgiving former United captain Keane might not appear to be a natural candidate to sympathetically attend his bedside, yet his presence amid that hospital horror story was uplifting in more ways than one.
"Roy came to visit me when I was at a low moment in the hospital," begins Cole, speaking to the Sunday World at a Bookmakers.com event in London.
"There he was stood at the end of my bed and it meant a lot. We had a laugh and a joke and it confirmed to me what I have always known - that he is a good-hearted person.
"He didn't need to spend his day in hospital trying to make me laugh, especially when he had been told by the doctors not to make me laugh as my stitches might come out!
"All I can say is he might have had some respect for me to go out of his way and visit me in hospital.
"He must have thought, 'I can relate to Coley, so I will go and make sure he is OK' and when people do that when you are at your lowest, it means so much.
"Roy was also very good during the Covid lockdown period checking in on me because he knows I had a few issues and that says all you need to know about the man.
"He is a genuine guy. People who see the angry fella on the TV or hear about his reputation don't know him.
"I judge him on how he has treated me, the conversations we have had and I know that he is always there on the end of the phone if I need anything. He is a real good guy."
Keane's reputation as a firebrand character has made him as compelling a character as he has been controversial down the years.
The 20th anniversary of his infamous fall-out with Ireland manager Mick McCarthy is looming large next month and that explosive reputation has cost him a chance to realise his ambitions as a manager.
Yet Cole suggests there could still be a way back for Keane as a coach, as he suggested modern players could benefit from the kind of straight-talking the Cork legend is famous for.
"People see Roy as some kind of man possessed and maybe he is on certain issues, but that's only because he sets high standards and expects people to come on the journey with him," added Cole.
"You don't have a lot of characters like Roy in dressing rooms any more. He would say what he thinks and it might get under people's skin at times and people might not like that.
"There were so many games when he stood up, took a game by the scruff of the neck and let everyone know they had to come with him or else. He let us know we were going to war here.
"If it is a problem for the modern day player to be spoken to in the way Roy can speak to you, I can't help them.
"He has only ever seen things in black and white. He has an opinion, you can either agree with him or disagree, but he won't change and some people can't deal with that.
"But that's what I like about him. His honesty is a good quality in my book. There is no hidden agenda with Roy. He says it as it is and in some ways, I wish more people were like him."
Cole went on to admit he faced a mental and physical battle to recover from his health crisis, as his bloated appearance was hard to accept and he was faced with the prospect of being changed forever.
"Before this, I would watch people who were depressed and suicidal and not really understand," added Cole, who is now campaigner for Kidney Research UK.
"Then I was in the same position. Depression kicks in, you have suicidal thoughts. The family understand it more than most, but I've pushed them to the brink.
"I finally realised my body was never going to be the same and that's difficult after being a sportsman all your life and being fit. It's very, very tough. It's been the toughest battle I've ever endured.