Now 36, the Leinster lock will bring his career to a halt this month once Leinster’s duties in the PRO12 play-offs end. A new life as the province’s forwards coach awaits, but he has already taken more from rugby than he could have ever dreamed.
Regrets? He surely has a few.
An Irish career that extended to just 32 caps is probably chief among them but he was humble enough this week to brush over any lows in a career which first came to prominence as part of Blackrock College’s ‘dream team’.
That 1996 vintage boasted Cullen and Bob Casey in the second row. Brian O’Driscoll, famously, had to make do with a slot on the bench as brighter stars such as Ciaran Scally and captain Barry Gibney held court.
It was players like those two, men whose celebrated talents and limitless potential were compromised so early by injury, who came to mind when Cullen was asked to sum up his days with clubs and country. “I’ve had more good days than bad,” he said.
“I’ve been pretty lucky. I’m 36 and I know guys from when I was younger who were probably a hell of a lot more talented than I was.
“Even sitting beside Brian, when I was leaving school I was playing in a team of 25 guys. If you were to say who the big star would be I probably would have picked six or seven guys ahead of him because it was very hard to see it back then.
“I was playing with guys who were pretty exceptionally gifted players and had the drive and the will as well. Injuries just struck them down when they were younger. That’s the way it goes. I think I’ve done all right.”
One last title is still within his grasp.
Tonight brings a seemingly routine outing at home to an Edinburgh side already in ‘beach mode’ and one where a win will ensure home advantage for the duration of the play-offs.
Leinster have been boosted by the return of Sean O’Brien for the first time since damaging his shoulder against Ulster last Christmas. A pretty spectacular recovery, all told, for a guy who had been ruled out until next season.
O’Brien is one of eight changes made by Matt O’Connor from the win in Ravenhill last week. Jordi Murphy and Jamie Heaslip complete the back row while Cullen replaces Devin Toner in the second row.
There is an all-new front row of Jack McGrath, Richardt Strauss and Mike Ross while, in the backs, Fergus McFadden takes Zane Kirchner’s slot out wide and the South African replaces Rob Kearney at full-back.
Jimmy Gopperth for Ian Madigan at 10 is the final switch for a game where Leinster actually require just the one point to guarantee a home play-off and two to wrap up top spot on the ladder. It will be double that, if not more.
Leo’s not done just yet.
LEINSTER: Z Kirchner, F McFadden, B O’Driscoll, G D’Arcy, D Kearney, J Gopperth, I Boss; J McGrath, R Strauss, M Ross, L Cullen, M McCarthy, S O’Brien, J Murphy, J Heaslip.
Replacements: S Cronin, C Healy, M Moore, R Ruddock, D Ryan, L McGrath, I Madigan, R Kearney.