In the five years since Ireland and South Africa last met in Dublin, James Ryan's career has seen peaks and troughs.
When he came on as a second-half replacement in November 2017 to make his home debut for Ireland, he was taking the early steps on his remarkable run which saw him play 21 games for province and country before tasting defeat.
"My first season was surreal," said Ryan, looking back on the 2017/18 season.
"We won the Grand Slam, the double [with Leinster] and I remember other lads saying to me: 'enjoy this, cherish it, days like this don't come around too often'.
"I was thinking 'what's this fellah talking about? This is my first season, what's going to be different next year?'
"But they were right. Having had some days where things haven't gone as well for us as a team, I appreciate weeks like this more."
When Ireland won their maiden Test series against New Zealand in the summer, you can imagine Ryan was giving similar advice to the likes of Joe McCarthy or Cian Prendergast.
The 26-year-old has been through as many downs as ups in the years since; a painful World Cup experience with Ireland in 2019, a Lions snub in 2021, and most importantly an extended period of being stood down from the game due to concussion.
But he looked close to his best on the summer tour in New Zealand, as well putting in some solid performances in the early rounds of the BKT United Rugby Championship.
He will win his 47th Test cap against the Springboks, although the prospect of that seemed unlikely when he suffered what looked like a serious knee injury last month against Connacht (below).
Buckling over on his knee at a ruck, he instantly feared the worst. To his relief, as well as Ireland coach Andy Farrell, he was fit enough to play the full 80 against Munster eight days later.
"Well, you always think ACL," said Ryan, recalling the incident at the Sportsground.
"That's the first thing you think of, so initially I was thinking 'oh f***’ but when the physio ran on and they did those tests I kind of knew it wasn’t too bad.
"The lads were slagging me. I got a poach in the first half, one of my first poaches probably in my career, got a bit ahead of myself, went for another one. But it was just an awkward position to be in and once someone kind of comes flying in… it just kind of crumpled underneath me and felt like a crunch behind my knee, which is never a good sign but they think it was just the joints kind of flicking off each other or whatever it was.
"It kind of went away then. I was a bit sore for about five or 10, 15 seconds and then it was fine. So I’m pretty lucky because you’ve seen other guys with a lot worse injuries in those positions before."
Having had to see a concussion specialist following a brain injury last November against Argentina, there were fears for the player's future in the game when he suffered another concussive incident against England in the Six Nations, returning eight weeks later for Leinster in the quarter-finals of the Heineken Champions Cup.
And he says the summer series win in New Zealand has given him a lot of confidence.
"I think the big thing was I was just getting a bit of confidence back. It had been a tricky couple of seasons in terms of the head injuries and the extended periods I had on the sidelines and being in and out of the game a bit.
"It definitely took a while when I got back at the latter end of last season, I suppose, it’s a contact sport, to find my confidence to go and hit things again and to feel like I was at my best again.
"Probably by the time the New Zealand tour came around, although we had a very disappointing number of weeks with Leinster, I played Leicester, Toulouse and La Rochelle, Glasgow and the Bulls, so I had a number of games under my belt. I suppose I was at a point where I wasn’t thinking about my head as much and was more thinking about my game and putting my best foot out there.
"Any sports career is full of ups and downs and probably last season again was kind of disappointing windows for me, so to finish last season in that manner where we put in, obviously the last two performances were very good and I was happy with my own personal performances as well.
"It was very satisfying for me to put that season away with an ending like that, for want of a better word."
The South Africa team that Ryan will face tomorrow looks a far different proposition to the side he faced in 2017.
And the Leinster man agrees with head coach Andy Farrell that it doesn't get much bigger than the world champions.
"I think this is the biggest test. I think they're the best team in the world so yeah, it's exciting for us to play against them.
"I came off the bench against them in 2017 and that was my first game in the Aviva. A lot of the same guys who will be playing were there that day, but obviously they're a much stronger team now.
"For us it's all about winning. That's what it's all about this weekend. We have an opportunity to play against a big, power-based team this weekend and it's exciting, we'll see where we're at at the back end of it."
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