The Manchester United winger reaches the latest milestone of his spectacular career tomorrow, which will be the prelude to him joining a select band of players who have appeared in the Premier League after entering their fifth decade.
It goes alongside his 13 Premier League titles, four FA Cups and two Champions Leagues, the stand-out moments from a glittering career that, following his spellbinding appearance in Wednesday night's 5-0 Champions League romp over Bayer Leverkusen, now also extends to 953 United games.
And Irwin, who spent 12 years as a team-mate of Giggs at Old Trafford, is certain they will not be matched.
Speaking at Chevrolet retailer Frosts of Shoreham, Irwin said: "That volume of medals will never be broken.
"What he has done is unbelievable. That kind of longevity at such a top club.
"This is no run of the mill mid-table team or one in the Championship. You are talking the very highest level for the last 23 years.
"The amount of games. The number of trophies. The dedication needed to go the distance and challenge yourself every year.
"To come back for pre-season training and keep going with the same intensity shows what type of player and person he is."
As the man who limped off injured in the game against Everton at Old Trafford on March 2, 1991 to herald Giggs' introduction, Irwin played a unique role in the Welshman's career.
For well over a decade, the pair patrolled the left-hand side of the field. Giggs was the flamboyant winger, Irwin Sir Alex Ferguson's Mr Dependable.
But the Irishman has a secret. He doesn't believe his own contribution could have been possible without Giggs' assistance.
"He wasn't afraid to do his defensive duties. He would always do the dirty side of things.
"It was a pleasure to work with him. He made my job a hell of a lot easier."
After sharing in so many triumphs, the actual volume of Giggs' medal haul is not something that particularly startles Irwin.
As Irwin acknowledged, once players reach their mid-30s, they tend to get bracketed as veterans and their actual age is forgotten.
Yet, in much the same way as they develop from 25 to 30, so the change continues from 35 to 40.
Having reached the age of 38 before calling time on his own career, Irwin is acutely aware of the effort Giggs has put into the latter years of his career.
"At that age, all you need are two or three indifferent games and the end of the horizon starts to come into view," said Irwin.
"I played a lot the year before but in my final season at Wolves I hardly figured over the last two or three months because I was finding it so tough.
"I know Ryan probably doesn't play as many games as he would like but you still have to train the same way.
"You can't lighten the workload. You need to do exactly the same to show that you can go the pace of the Premier League.
"For him to continue for the past six or seven years, play the amount of games he has and win all those trophies at the very top level is unbelievable."