It was good of John Delaney to cover for me the way he did, writes Frank McNally. But now that Denis has been outed, it's only a matter of time before somebody leaks the full story to the red-tops. So you might as well find out here. Yes, I am the mystery benefactor who put up the other half of Giovanni Trapattoni's salary.
Before I explain the motivation behind my offer, let me assure the public that - as in Mr O'Brien's case - there were no strings whatsoever attached.
The choice of manager was entirely a matter for the three-man selection panel. Nor does my investment entitle me to any influence over team selection, beyond a verbal understanding that if Robbie Keane ever revives his annoying bow-and-arrow goal celebration, he will be dropped for the next two games.
Like Denis's, my offer was born from simple altruism. Life has been good to both of us. My South American mining interests continue to be very lucrative, thank God.
And when I took that 5 per cent share in a start-up company called Google some years ago, I could hardly have foreseen how it would flourish.
Above all, ever since the age of 15, when I was arrested on a minor shop-lifting offence, I have always been a great believer in the idea that you should give something back.
My relationship with the FAI had until recently been one of take-take-take: a succession of joy-filled nights watching the team fight out thrilling 1-1 draws at home to Cyprus and the like. Finally it was time to repay the debt.
Until Wednesday, I thought mine was the only contribution to the new manager's salary. It was, frankly, a little disappointing to learn that Denis had had the same idea. When I floated the proposal to the FAI last July - er, I mean the day after Steve Staunton's resignation in November - they seemed genuinely surprised.
So I can only presume they hadn't heard from Denis yet.
But whichever of us thought of it first (me!), it seems we were both inspired by the same source.
I note that Denis says he acted after a conversation with Eddie Jordan, who told him: "We should give a hand out and maybe get somebody really good".
Funny enough, that's exactly what Eddie said to me too.
I can't help wondering now about his use of the term "we" when it was only Denis and I that actually coughed up. But maybe Eddie is even more modest than either of us.
Perhaps he has offered to contribute the third half of Trapattoni's salary, and the FAI are just keeping quiet about it.
My sporting philanthropy extends beyond soccer, incidentally, but I won't go into details here. Oh all right, you dragged it out of me.
When the GAA first proposed redeveloping Croke Park, and there was a risk they might settle for less than a world-class stadium, somebody said to me - again it was probably Eddie - that "we should give a hand out and get something really good".
There were no strings attached to my offer - 50 per cent of the new stadium's cost - then either. I certainly didn't want publicity.
And it was only when the GAA insisted on honouring me in some way that a compromise was reached whereby I allowed them to attach part of my surname - 50 per cent again - to one of the smaller structures.
The beauty of the arrangement is that there had been a Nally Stand on the same site for half a century, so the GAA's need to acknowledge their benefactor was not done at the expense of his modesty.
Of course there are more important things in life than sport.
Suffice to say I have never been found wanting when the general national interest calls.
I believe strongly that if you hire the right people you get the right results.
So whenever a public body is in the market for a chief executive and there is a risk that the official rate will not attract the right calibre of candidate, my cheque-book is always at the State's service.
Back in the mid-1990s, for example, I heard there was about to be a vacancy for the job of Taoiseach.
I was drinking with some fellow philanthropists at the time and one of them said that maybe we should give a hand out and get somebody really good.
So we Googled the various candidates and discovered that Bertie Ahern had by far the most impressive CV.
St Joseph's Fairview, UCD, London School of Economics: you name it, he'd done it. "Wow!" I said. "Imagine if we could get him."
Yes, there were concerns about whether he had enough English for the job. But it was clear to me he was the man to lead Ireland. It was equally clear that the salary on offer would not be enough for such a high-quality candidate.
So a few of us offered to contribute on a no-strings-attached basis.
We were rather taken aback when the offer was declined. It turned out that others had got there before us and Mr Ahern was already funded by a public-private partnership.
The main thing is, he took on the job and the rest is history. But it's a very competitive area, philanthropy.
You'd be amazed just how many of us there are out there, working quietly behind the scenes for the betterment of people's lives.