Until now that is.
Over the years he has always struck me as a little too forthright in his opinions, and a little too dramatic in his actions.
Whenever Cusack has publicly defended the Gaelic Players Association, a body he is so closely involved with, or the striking Cork hurlers he has almost come across as arrogant.
He never saw anything wrong with the way the Cork players stayed away from their county team last season, nor did he seem too upset by the manner in which their strike effectively killed off Gerald McCarthy’s managerial career.
Cusack has always staunchly defended any movement or cause he has been involved with and for that he is to be commended, even if I didn’t always agree with the principles involved, but he may now be facing into his biggest fight yet.
This weekend Cusack landed himself at the center of a media storm and it was all of his own volition, with the legendary ‘keeper just about to publish a groundbreaking autobiography for a GAA player, one in which he admits he is gay.
Now a friend of mine who covers Gaelic games for a living claimed recently that the only way to get attention for a GAA book is to admit to being an alcoholic, a drug addict or a wife beater, all of which have been covered in recent tomes by former players.
Outing yourself as a gay man in the macho world of Irish sport and the conservative world of the GAA did not feature on my colleague’s list.
Simply, I suspect, because he didn’t believe any footballer or hurler still playing his sport at the highest level would admit to such a thing.
That’s not the only reason why Cusack is to be commended for his honesty, even if it could yet come back to bite him.
Considering some of the media hype in Ireland surrounding his admission he may have been ill-advised to come out so publicly, but he is definitely brave to do so.
As well as shock in some conservative circles, there is definitely an air of surprise at the news that one of the country’s top hurlers is gay.
The image doesn’t fit with that of the stereotypical hard man excelling our national game, but why should we surprised by the news?
And why should Donal Og Cusack be treated with anything but respect by those who follow his sport, and those who write about it?
There were suggestions in Tuesday’s papers that Cusack will now announce his retirement from the game he loves in the wake of the reaction to his revelations, but I hope not.
Coming clean may be a painful process for Cusack in the short term, but ultimately he has done Irish society, never mind the GAA, a favor with his honesty and his bravery.
He has brought a taboo subject to the fore in Irish sport, and he has dragged his sport into the modern age. For that I salute him.