"There have been many occasions when I have been heading home from an evening match at one or two in the morning and Gerard has rung me on my car phone," said O'Leary.
"He's like an owl, working away at night. He'd call just to talk about our match and Liverpool's fixture the following night. All Gerard has apart from a fantastic family, is football, football, football. He can't switch off, he's a workaholic."
Talking about Ged's health, O'Leary said: "I don't think Gerard helped his own general health. He was carrying a touch too much weight and not getting enough exercise."