The Cardiff Blues prop is set to join Welsh centurions Stephen Jones, Gareth Thomas and Martyn Williams when he runs out against Millennium Stadium visitors Argentina.
It is 11 years since Jenkins, who will be 33 on Sunday, featured for his international debut against Romania on a Friday night in Wrexham.
Long since established among the finest loosehead operators rugby union's professional era has seen, he has also had a fair share of setbacks, highlighted by this summer's British and Irish Lions tour to Australia when he flew 10,000 miles and did not play a game.
"It was probably one of my lowest points," said Jenkins, reflecting on the calf muscle problem that meant an early journey home from Down Under.
"Having to leave the Lions tour after working four years to get there, getting selected and then having to go home was tough."
But many highs have accompanied him on the road to hitting three figures, notably four Six Nations titles, three Grand Slams and a World Cup semi-final.
And the accolades have rightly flowed this week, with Wales coach Warren Gatland describing him as "a sensational player," assistant coach Rob Howley as "phenomenal" and his team-mate Mike Phillips hailing Jenkins "exceptional" ability.
"I suppose it's a weight off my mind, really," added Jenkins, on getting to 100 caps.
"After the game on Saturday perhaps I will think about it a bit more because you are so tied up in the week with the build-up to the game. I suppose that afterwards I can look back and think, 'Yes, I got to 100'.
"The game has got a lot more physical over the last few years. It has completely changed from the way it was when I first started.
"I don't remember much about my first cap, althhough I do remember being pretty nervous before it. It was up in Wrexham, which was a bit different from the Millennium Stadium, but I can't remember anything that happened in the game."
For the record, Wales won 40-3 and Mefin Davies and Martyn Madden were Jenkins' front-row colleagues, but there is a neat symmetry between now and then - the influence on him of Gatland and his fellow New Zealander, the current All Blacks chief Steve Hansen.
"Steve Hansen was the first coach I had with Wales," Jenkins said. "He had a lot of belief in me when I was quite young and brought me through into the system.
"He focussed on team values a lot and brought us on through a system and took it on for the next few years, really.
"Warren and the coaching staff now have brought it on to a different level, and for me it was adapting to the game and its changes. You see some boys fall away when the game changes, but I am happy that I have managed to adapt.
"I still like to do the stuff away from the scrum, but in the last three or four years there has been a lot more emphasis on the scrum and a lot more responsibility on you to work hard in that area.
"Previously, it was perhaps more of a looser game and defences weren't as good, but you just have to adapt. I pride myself on getting around the field, and there are no hiding places now, either.
"You have got a GPS on your back and a heart-rate device on your chest, so they (coaches) know everything you are doing. And on top of that, Warren's mentality is 'work as hard as you can,' which suits me."
Jenkins has the 2015 World Cup set as a firm target, but Saturday will also be a time to reflect with his family on an international career packed with memorable moments.
"Probably the Grand Slam game of 2005 against Ireland sticks out - just for the simple fact I scored a try!" he added.
"That day was massive because it was the first time we had done it (Grand Slam) in 20-odd years, and to be a big part of it and score a try was a great memory.
"I think the family are all going down on Saturday to watch. Mum and dad followed me everywhere, really, up until 2007 when my mum died.
"My dad will be there, it will be a great day for the family, and I am sure it will have a bit of an effect on me during the anthem. Normally, the anthem is when you think about things like that, and then you switch on for the game."