He's been capped 105 times by Ireland and on Monday, will become Munster's second most capped player - after Peter Stringer - when he runs out for the 217th time in the game against Connacht.
Perhaps his great strength, evidenced yet again today, is his modesty. That and a genuine astonishment that there should be any fuss at all about himself, whether that be to do with his achievements, his longevity in the most demanding department of rugby or his contribution to Munster and Irish rugby. Unassuming simply doesn't cover it when you talk about John Hayes.
When coach Tony McGahan was asked about him he said, "When I speak of the John Hayes I've known in my time time here I'd speak of John as the person more than anyone else. I think just his general demeanour. Who he is and what he's about has always been about the team and that's been evident all the way through. Even for him to sign on after the World Cup to help us out of a situation gives you a measure of the man.
"Y'know, whenever there was a Cork game on he was the first man down there in the dressing room after the game. He has a young family, lives the other side of town and guys who lived 10 kilometres away didn't bother going. But he was always the first one down there. And for me that really speaks volumes of who he is.
"It didn't matter who you were in the squad, first in say like myself when I arrived, he always had time for you. Didn't matter whether you were staff or player, anyone, it didn't matter. He treated everyone the same. His legacy as a person will be one of the abiding features of him here at Munster."
This afternoon, Hayes applied himself to his job with the same focus as any of the other countless sessions he's been involved in. He scored his fifth and perhaps final try for Munster in the course of the short game refereed by George Clancy and afterwards had perhaps, the busiest afternoon of his career with the assembled media.
Then he stood and smilingly signed jerseys and posters for young and old alike.
And finally, after a Tony Mullins prepared meal shared with wife Fiona Steed, daughters, Roisin and Sally and teammates Denis Fogarty and Donncha O'Callaghan, Hayes retired to the bar.
To sign more posters and jerseys.