"In 2010, when Peter Fitzpatrick came in, he probably didn't see as much of Dublin football as maybe he could have seen. It was a shocking disappointment, a big one in my career to miss that Leinster final and play no part in it," he explains now, the benefit of a couple of impressively redemptive seasons with Louth behind him and having just recently moved back to his native club, St Mary's, Ardee.
Still . . . the snub rankles. And for Clarke, the digits still didn't add up.
"To me, playing in Dublin club championship games is the same standard as playing in Division 2 of the National League," he says without a whiff of exaggeration.
"It's a seriously high standard. But in some way, it probably counted against me. Out of sight, out of mind. At the time, Brian McEniff (one of Fitzpatrick's selectors) was pushing for me to get into the team so it was disappointing he wasn't listened to.
"I felt myself I should have been in there, or at least been used. It's an awful disappointment to look back on the Leinster final (v Meath) and think that you didn't play a part in it."
He had scored heavily for Louth in 2008 and '09 but the 2010 season and all its Leinster final melodrama was entirely a Darren Clarke-free zone.
"Then, when Peter sent a few people to go and watch me play with Sylvester's, it probably got me back into the team. It got me back going and my form picked up with the county when I got back in.
"But I suppose when I did get back in, I didn't do anything differently. I was still the same player as I was the year before. I just picked up where I left off in '08 and '09."
So in 2011, 2012 and already at this embryonic stage of 2013, he has figured prominently in Louth's scoring stats and hopes, niggling injury permitting, to play some part on Sunday when the Dubs come to Drogheda for their Bord na Móna O'Byrne Cup semi-final.
He was pleased to see Aidan O'Rourke appointed as Fitzpatrick's successor, that Louth were embracing the cult of the young manager and that those players who seemingly emigrated every other week last season are back in the squad and settled in Ireland.
He watched the repeat of the Páidí ó Sé documentary 'Marooned' the other night and noted how the manager's role in senior inter-county football is evolving and in that, he thinks O'Rourke is a snug fit.
"Páidí was a super manager, a super player and a GAA legend. He really showed his passion and that really came out in the Westmeath team in '04.
"But I think now the more modern managers, they're more inclined to think tactically and to think about systems rather than doing the geeing-up stuff."
He could, of course, come face-to-face with one of his old St Sylvester's colleagues Gary Sweeney on Sunday - a young player who was a central figure in both of Jim Gavin's All-Ireland U21 successes (2010, 2012).
Clarke is undoubtedly a big fan.
"Gary is a unique talent," he says. "He's one of these players who can change a game in a split second. He has the pace, he's accurate, he can pull a goal out of the bag. To me, he is what Dublin should be looking at and trying to make into their centre-forward for the next couple of years.
"He has all the attributes and all the qualities to be a fantastic player for Dublin in Croke Park. He has a great appetite for the game as well. He has won two All-Ireland under-21 titles already. It's time for him now to make the step up to the senior team."
Sweeney's absence with a broken leg last season greatly affected Syls preparations and championship hopes, Clarke says.
They went out in the quarter-final against Kilmacud Crokes, a familiar exit strategy but in his time, they won a Division 1 title in 2010, a 'B' Championship in 2008 and under Gabriel Bannigan, were transformed into one of the capital's strongest senior sides.
"We pushed the boat out a bit in the last few years but unfortunately, we didn't get to where we wanted in the championship," Clarke reflects now.
"But as the years went on, we got stronger and stronger. I played in five league semi-finals and two finals and I remember going down to watch the lads the first night training and where they were then compared to where they were when I left them.
"Unfortunately, it didn't happen in my time," Clarke adds, "but it's a great club. I loved my time there and hopefully, it will happen for the boys at some stage."